PM6600 STMicroelectronics, PM6600 Datasheet
PM6600
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PM6600 Summary of contents
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... PM6600TR February 2010 6-row 32 mA LED driver with boost regulator Description The PM6600 consists of a high efficiency monolithic boost converter and six controlled current generators (ROWs), specifically designed to supply LEDs arrays used in the backlight of LCD panels. The device can manage a nominal output voltage ...
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... Switching frequency selection and synchronization . . . . . . . . . . . . . . . . . 28 7.4 System stability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 7.4.1 7.4.2 7.5 Soft-start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 7.6 Boost current limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 7.7 Enable function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 7.8 Thermal protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 8 Backlight driver section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 8.1 Current generators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 8.2 PWM dimming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 2/60 Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Loop compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Slope compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Doc ID 14248 Rev 7 PM6600 ...
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... A.3 LX area – vout power area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 A.4 Overvoltage divider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 A.5 LDO5 – AVCC filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 A.6 ROWs current generators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 A.7 Top layer of the standard PM6600 demonstration board Appendix B Application note B.1 Inductor selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 B.2 Capacitors selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 B.3 Flywheel diode selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 B.4 Design example ...
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... Contents Appendix C Application suggestions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 C.1 Full application schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 C.2 EN, DIM path in production line C.3 ROW pins protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 C.4 Debug and measurements test points C.5 Inductor choice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 11 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 4/60 Doc ID 14248 Rev 7 PM6600 ...
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... PM6600 List of figures Figure 1. Application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 2. Pin connection (through top view Figure 3. Efficiency vs DIM duty cycle @ fDIM = 200 Hz Figure 4. Efficiency vs DIM duty cycle @ fDIM = 500 Hz Figure 5. Efficiency vs DIM duty cycle @ fDIM = 1 kHz Figure 6. Efficiency vs DIM duty cycle @ fDIM = 5 kHz Figure 7. ...
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... Figure 54. Top layer critical signals components assembly and layout . . . . . . . . . . . . . . . . . . . . . . . . 46 Figure 55. Top side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Figure 56. Bottom side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Figure 57. Inductor current in DCM operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Figure 58. Full application schematic Figure 59. EN pin filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Figure 60. DIM pin filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Figure 61. ROW pins protection 6/60 Doc ID 14248 Rev 7 PM6600 ...
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... PM6600 1 Typical application circuit Figure 1. Application circuit LX 19 BILIM VIN 8 RILIM SYNC 23 Doc ID 14248 Rev 7 Typical application circuit SGND FSW 4 7/60 ...
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... V analog supply. Connect to LDO5 through a simple RC filter. Internal +5 V LDO output and power section supply. Bypass to SGND with a 1 µF ceramic capacitor. Input voltage. Connect to the main supply rail. Doc ID 14248 Rev 7 Function Section 7.3 on page 28 for details. for details. PM6600 ...
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... PM6600 Table 2. Pin functions (continued) N° Pin 9 SLOPE 10 SGND 11 ROW1 12 ROW2 13 ROW3 14 ROW4 15 ROW5 16 ROW6 17 PGND 18 OVSEL DIM FAULT 23 SYNC 24 SS Slope compensation setting. A resistor between the output of the boost converter and this pin is needed to avoid sub-harmonic instability. Refer to section 1.4 for details. ...
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... Thermal data Table 4. Thermal data Symbol R Thermal resistance junction to ambient thJA T Storage temperature range STG T Junction operating temperature range J T Operating ambient temperature range A 10/60 (1) Parameter Parameter Doc ID 14248 Rev 7 PM6600 Value Unit -0 -0 -0.3 to 0 0.3 AVCC - ...
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... PM6600 3.3 Recommended operating conditions Table 5. Recommended operating conditions Symbol Supply section V Input voltage range IN Boost section V Output voltage range BST Adjustable switching f SW frequency FSW sync input duty-cycle ROWs output maximum I rowx current Parameter FSW connected to R FSW Doc ID 14248 Rev 7 ...
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... Test condition EN High LDO5 kΩ, RILIM R = 220 kΩ, BILIM R = 680 kΩ SLOPE DIM tied to SGND. EN low LDO5 LDO5 V > V LDO5 UVLO,ON V < V LDO5 UVLO,OFF Doc ID 14248 Rev 7 PM6600 (1) . Values Unit Min Typ Max 4 μ 4.6 4.75 V 3.8 4 120 ...
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... PM6600 Table 6. Electrical characteristics (continued) Symbol Parameter Boost section Minimum switching t on,min on time Default switching frequency Minimum FSW Sync frequency FSW sync Input low level threshold FSW sync Input hysteresis FSW sync Min ON time SYNC output duty-cycle SYNC output high level ...
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... The current mismatch is the maximum current difference among the ROWs of one device. 14/60 Test condition kΩ RILIM kΩ RILIM ( kΩ RILIM No LEDs mismatch FAULT,SINK Doc ID 14248 Rev 7 PM6600 Values Unit Min Typ Max 1.6 0.8 V 1.3 0.8 2.5 μ 2.4 2 ...
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... PM6600 5 Typical operating characteristics All the measures are done with a standard PM6600EVAL demonstration board and a standard WLED6021NB tamboured, with the components listed in the EVAL_KIT document. The measures are done with this working conditions, unless specified: ● Vin = 12 V ● Vout = 6 rows x 10 WLEDs = 34 V (typ) ● ...
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... DIM duty cycle [%] DIM duty cycle @ Vin = DIM duty cycle [%] PM6600 Vin = 6V Vin = 12V Vin = 18V Vin = 24V 80 100 80 100 fDIM = 200Hz fDIM = 500Hz fDIM = 1kHz fDIM = 5kHz fDIM = 10kHz fDIM = 20kHz ...
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... PM6600 Figure 13. Efficiency vs Vin @ DIM duty cycles = 10% 100 Vin [V] Figure 15. Efficiency vs Vin @ DIM duty cycles = 75 Vin [V] Figure 14. Efficiency 100 fDIM = 200Hz fDIM = 500Hz 40 fDIM = 1kHz 30 fDIM = 5kHz 20 fDIM = 10kHz fDIM = 20kHz Figure 16. Efficiency fDIM = 200Hz 91 fDIM = 500Hz 90 fDIM = 1kHz fDIM = 5kHz ...
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... Typical operating characteristics Figure 17. Working waveforms @ f = 100 Hz DIM Figure 19. Working waveforms @ f = 100 Hz 50% DIM 18/60 Figure 18. Working waveforms @ f = 100 Hz 10% DIM Figure 20. Working waveforms @ f = 100 Hz 80% DIM Doc ID 14248 Rev 7 PM6600 ...
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... PM6600 Figure 21. Working waveforms @ f = 200 Hz DIM Figure 23. Working waveforms @ f = 200 Hz 50% DIM Typical operating characteristics Figure 22. Working waveforms @ f = 200 Hz 20% DIM Figure 24. Working waveforms @ f = 200 Hz 80% DIM Doc ID 14248 Rev 7 19/60 ...
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... Typical operating characteristics Figure 25. Working waveforms @ f = 500 Hz DIM Figure 27. Working waveforms @ kHz DIM 20/60 Figure 26. Working waveforms @ f = 500 Hz 50% DIM Figure 28. Working waveforms @ kHz 50% DIM Doc ID 14248 Rev 7 PM6600 ...
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... PM6600 Figure 29. Working waveforms @ kHz DIM Figure 31. Working waveforms @ kHz DIM Typical operating characteristics Figure 30. Working waveforms @ kHz 50% DIM Figure 32. Working waveforms @ Hz 50% DIM Doc ID 14248 Rev 7 21/60 ...
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... Typical operating characteristics Figure 33. Output voltage ripple @ f = 200 Hz DIM Figure 35. Output voltage ripple @ f = 200 Hz 50% DIM 22/60 Figure 34. Output voltage ripple @ f = 200 Hz 20% DIM Figure 36. Output voltage ripple @ f = 200 Hz 80% DIM Doc ID 14248 Rev 7 PM6600 ...
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... PM6600 Figure 37. Shorted LED protection @ f = 200 Hz DIM all WLEDs connected Figure 39. Shorted LED protection @ f = 200 Hz DIM 2 WLEDs shorted Typical operating characteristics Figure 38. Shorted LED protection @ f DIM 1 WLED shorted Figure 40. Shorted LED protection @ f DIM 3 WLEDs shorted - ROW disabled Doc ID 14248 Rev 7 = 200 Hz ...
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... Typical operating characteristics Figure 41. Open ROW detection @ f = 200 Hz DIM 24/60 Doc ID 14248 Rev 7 PM6600 ...
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... PM6600 6 Block diagram Figure 42. Simplified block diagram LDO5 COMP BILIM SS SYNC Ext Sync Detector FSW AVCC EN MODE FAULT DIM Shutdown VIN SLOPE Current Sense Ramp +5V ZCD Generator LDO + + + UVLO _ Control Detector UVLO + 0. Boost_EN Current Limit Min Voltage Soft Start Selector Prot_EN ÷ ...
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... Boost section 7.1.1 Functional description The PM6600 is a monolithic LEDs driver for the backlight of LCD panels and it consists of a boost converter and six PWM-dimmable current generators. The input voltage range is from 4 The boost section is based on a constant switching frequency, Peak Current-Mode architecture ...
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... V threshold. When the voltage on the OVSEL pin exceeds the OV threshold, the FAULT pin is tied low (see condition is latched and the PM6600 is restarted by toggling the EN pin or by performing a power-on reset (the POR occurs when the LDO output falls below the lower UVLO threshold and subsequently crosses the upper UVLO threshold during the rising phase of the input voltage). Normally, the value of the high-side resistors of the divider is in the order of 100k Ω ...
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... Equation 6 In addition, when the FSW pin is tied to AVCC, the PM6600 uses a default 660 kHz fixed switching frequency, allowing to save a resistor in minimum components-count applications. Figure 45. Multiple device synchronization ...
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... PM6600 The SYNC pin is a synchronization output and provides a 34% (typ.) duty-cycle clock when the PM6600 is used as master or a replica of the FSW pin when used as slave used to connect multiple devices in a daisy-chain configuration or to synchronize other switching converters running in the system with the PM6600 (master operation). ...
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... Operation description 7.4 System stability The boost section of the PM6600 is a fixed frequency, peak current-mode converter. During normal operation, a minimum voltage selection circuit compares all the voltage drops across the active current generators and provides the minimum one to the error amplifier. The output voltage of the error amplifier determines the inductor peak current in order to keep its inverting input equal to the reference voltage (400 mV typ) ...
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... PM6600 Equation 9 Once the output capacitor has been chosen, the R Equation 10 Where G = 2.7 S and g M The C capacitor is determined to place the frequency of the compensation zero 5 COMP times lower than the loop bandwidth: Equation 11 Where The close loop gain function (G Equation 12 A simple technique to optimize different applications is to replace R trimmer and adjust its value to properly damp the output transient response ...
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... LDO5 ROW1 ROW2 BILIM PM6600 ROW3 RILIM ROW4 SS ROW5 COMP SGND ROW6 PWM g m 0.4V Doc ID 14248 Rev 7 V BST=30÷36V 4.7μF MLCC WLEDs per row ROWx Minimum voltage drop selector PM6600 V BST = L 50mA 500Hz SGND RILIM ...
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... PM6600 The SLOPE pin allows to properly set the amount of slope compensation connecting a simple resistor R starts at 35% (typ.) of each switching period and its slope is given by the following equation: Equation 13 Where SLOPE To avoid sub-harmonic instability, the compensating slope should be at least half the slope of the inductor current during the off-phase for a duty-cycle greater than 50% (i ...
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... Please refer to the application note section for the CSS value settings according to the different working conditions. 34/60 Floating ROWs detection 93% of OVP Protections turn active ≅ Doc ID 14248 Rev 7 Output voltage SS pin voltage Nominal switching frequency release Current limit EN pin voltage t Table 8 (see Section 9 on page PM6600 ...
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... Equation 17 b 7.7 Enable function The PM6600 is enabled by the EN pin. This pin is active high and, when forced to SGND, the device is turned off. This pin is connected to a permanently active 2 μA current source; when sudden device turn-on at power-up is required, this pin must be left floating or connected to a delay capacitor ...
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... FAULT pin low. In order to turn on the device again possible to perform a POR (power on reset) once the junction temperature has been reduced by 30 °C. 36/60 enabling schematic DIM BAS69 EN 220k 100n Doc ID 14248 Rev 7 PM6600 SGND PM6600 ...
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... Backlight driver section 8.1 Current generators The PM6600 is a LEDs driver with six channels (ROWs); each ROW is able to drive multiple LEDs in series (max and to sink maximum current, allowing to manage different kinds of LEDs. The LEDs current can be set by connecting an external resistor (R pin and ground. The voltage across the RILIM pin is internally set to 1.2 V and the ROWs ...
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... ROW _ − Δ = ROW _ min ROW I ROWx , min I ROW _ mean 6 ∑ I ROWi = = ROW _ mean 500 ns DIM , min = 0 Hz. However, in order to avoid any flickering DIM Doc ID 14248 Rev 7 I ROW _ mean ≤ mean _ mean ≥ − ⋅ f DIM > 100 Hz (condition DIM . sw PM6600 ...
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... MODE pin The MODE pin is a digital input and can be connected to AVCC or SGND in order to choose the desired fault detection and management. The PM6600 can manage a faulty condition in two different ways, according to the application needs. detects and handles the internal protections related to the boost section (over-current, over- temperature and over-voltage) and to the current generators section (open and shorted LEDs) ...
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... ROWs, without asserting the FAULT pin. Connecting the MODE pin to SGND, the PM6600 behaves in a different manner: as soon as one open ROW is detected, the FAULT pin is tied low. In case a second open ROW is detected, the device is turned off ...
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... PM6600 If the fault disappears after toggling the EN pin, it means that the connection is again on and the problem can be detected as a previous intermittent connection. If the fault persists also after toggling the EN pin, it means that the problem is on the leds (one or more open leds the flat cable or the cable connector (broken wire). ...
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... VFQFPN-24 mechanical data Table 10. Dim ddd 42/60 Min Typ 0.80 0.90 0.00 0.02 0.20 0.18 0.25 3.85 4.00 2.40 2.50 3.85 4.00 2.40 2.50 0.50 0.30 0.40 Doc ID 14248 Rev 7 PM6600 ® Max 1.00 0.05 0.30 4.15 2.60 4.15 2.60 0.50 0.08 ...
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... PM6600 Figure 53. VFQFPN-24 mechanical data Doc ID 14248 Rev 7 Package mechanical data 43/60 ...
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... A.1.2 GNDs planes - 3 devices (RGB) The SGND plane is the same for all the PM6600 devices – bottom layer (or internal 2-3). Each PM6600 device must have its own PGND area (top layer), connected to the main SGND in one point, near the PGND pin of each device > totally 3 connections between the SGND and PGND, 1 for each driver: PGND_red - SGND ...
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... A.4 Overvoltage divider Since the PM6600 works with a compensated divider connected to the OVSEL pin to set the Overvoltage threshold, the two capacitors should be mounted as close as possible to the OVSEL pin of the device. Then you can choose the resistors position near of them. ...
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... GND plane connected to SGND and PGND with the vias on the thermal pad and the vias inside the test points. Since the PM6600EVAL_EN demonstration board is an isolated system, there are no cross- talking issues between the GNDs areas. When the device is mounted on a LCD board, together with other devices (digital, analog and power ones very important to properly follow the layout guidelines listed above, in order to dedicate to each device the PGND and SGND portion of the entire board ...
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... PM6600 The following pictures are the Gerber files of the PM6600EVAL_EN board. Figure 55. Top side Figure 56. Bottom side Vias specs: diameter 0.8 mm, hole 0 Doc ID 14248 Rev 7 Layout guidelines 1.1 cm 47/60 ...
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... As in most of boost converters, the input capacitor is less critical, although it is necessary to reduce the switching noise on the supply rail. The input capacitor is also important for the internal LDO of the PM6600 and must be kept as close as possible to the chip. The rated voltage of the input capacitor can be chosen according to the supply voltage range µF X5R MLCC is recommended ...
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... PM6600 B.4 Design example In order to help the design of an application using the PM6600, in this section a simple step- by-step design example is provided. A typical application could be the LCD backlight in a 14.1” LCD panel using the PM6600. Here below the possible application conditions are listed: ● ...
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... An inductor value of 6.8 µH could be a suitable value, considering also a margin from the boundary condition. 50/60 ⎧ − ⎨ ⎩ OUT OUT OUT = ⋅ OUT ROW = ⋅ OUT , max , F LEDs , max 1 < min Doc ID 14248 Rev min = max Ω 250 120 400 will be at the lower input voltage. Hence μ PM6600 t t ...
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... PM6600 It is important to highlight that the inductor choice involves not only the value itself but the saturation current (higher than the boost current limit), the rated RMS current (the compliance with the saturation current might be not enough; also the thermal performances must be taken into account), the DCR (which affects the efficiency) and the size (in some application might be a strict requirement) ...
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... OUT lower than 80 mV (i.e. the 20% of the voltage across the OUT ( ) − ⋅ > peak OUT C OUT Δ ⋅ OUT , max ⎛ ⎜ OVP ⎝ 235 Doc ID 14248 Rev min = @ max IN,min OFF = μ ⎞ − ⎟ 1 ⎠ PM6600 = 9.6 V). ...
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... PM6600 V has to be chosen in the range OVP Equation 37 Where Equation 38 R can be chosen is in the order of hundreds of kilo-ohms to reduce the leakage current in 1 the resistor divider. For example, setting R The OVSEL divider capacitors should be chosen according to the formula Equation 39 For most cases, C10 = 220 pF and C13 = 22 pF are recommended. ...
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... SLOPE are changed to lower the amplitude of the overshoot for 7.5 V<V Doc ID 14248 Rev 7 is, in this case, 6.8 nF. SS < 6 ROWs application 6.8 nF 200 kΩ 1 MΩ 3.3 kΩ 3.3 nF overshoot with OUT PM6600 results SS < ...
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... MOD E With respect to the Basic application circuit (see chapter1), some optional components are added. Below the suggestions, section by section, on why and in which cases to add these components 15u > AVC C O VSEL ilt SLO ldo 1uF 22 FAU LT PM6600 MOD COMP 3nF ilim R bilim ...
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... In case the DIM signal is provided by a micro controller (in production line and/or in the final application), a pull-down resistor Rdim2 can be needed. If the micro controller is not powered possible that the voltage on the DIM pin of the PM6600 device will logic high level, because of board noise or signals coupling. The pull-down resistor avoids this issue ...
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... PM6600 In case of the DIM pin, we suggest to use a function generator. In case of using a power supply preferable to use 3.3 V and the same RC filter as the EN pin. For what concerns the VIN pin already filtered by the input capacitors. C.3 ROW pins protection Figure 61. ROW pins protection In the production line, the most common way to test the LED Driver PCB is to connect it to the LED Board using a Dummy LED Driver Board ...
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... If the saturation is prolonged, the inductor is behaving as a wire (the inductance value will be extremely reduced). This will create inductor damage and/or device damage because of overstress condition. 58/60 Section B.4.3: Inductor choice on Doc ID 14248 Rev 7 PM6600 ...
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... PM6600 11 Revision history Table 12. Document revision history Date 07-Dec-2007 21-Jan-2008 07-Apr-2008 20-Oct-2008 12-Feb-2009 29-Jun-2009 18-Feb-2010 Revision 1 Initial release 2 Updated Table 4, Table 5 3 Updated Section 3.3 on page 11 Updated Section 3.3 on page 11 4 Added Section Appendix A on page 55 Added Figure 58 on page 5 page 55, Section C ...
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... Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America 60/60 Please Read Carefully: © 2010 STMicroelectronics - All rights reserved STMicroelectronics group of companies www.st.com Doc ID 14248 Rev 7 PM6600 ...