EVALED2000P STMicroelectronics, EVALED2000P Datasheet

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EVALED2000P

Manufacturer Part Number
EVALED2000P
Description
LED Lighting Development Tools LED2000 3A 850KHz 3.0V to 18V Eval BRD
Manufacturer
STMicroelectronics
Datasheet

Specifications of EVALED2000P

Product Category
LED Lighting Development Tools
Rohs
yes
Product
Evaluation Boards
Operating Supply Voltage
3 V to 18 V
For Use With
LED2000
Features
Applications
Figure 1.
October 2012
This is information on a product in full production.
3.0 V to 18 V operating input voltage range
850 kHz fixed switching frequency
100 mV typ. current sense voltage drop
PWM dimming
Synchronous rectification
95 m HS / 69 m LS typical R
Peak current mode architecture
Embedded compensation network
Internal current limiting
Ceramic output capacitor compliant
Thermal shutdown
High brightness LED driving
Halogen bulb replacement
General lighting
Signage
7% output current accuracy
Typical application circuit
DS(on)
3 A monolithic step-down current source
Doc ID 023432 Rev 3
Description
The LED2000 is an 850 kHz fixed switching
frequency monolithic step-down DC-DC converter
designed to operate as precise constant current
source with an adjustable current capability up to
3 A DC. The embedded PWM dimming circuitry
features LED brightness control. The regulated
output current is set connecting a sensing resistor
to the feedback pin. The embedded synchronous
rectification and the 100 mV typical R
voltage drop enhance the efficiency performance.
The size of the overall application is minimized
thanks to the high switching frequency and
ceramic output capacitor compatibility. The device
is fully protected against thermal overheating,
overcurrent and output short-circuit.
The LED2000 is available in VFQFPN 4 mm x 4
mm 8-lead package, and standard SO8.
VFQFPN8 4x4
with synchronous rectification
Datasheet — production data
LED2000
SENSE
SO8
www.st.com
1/40
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Related parts for EVALED2000P

EVALED2000P Summary of contents

Page 1

Features ■ 3 operating input voltage range ■ 850 kHz fixed switching frequency ■ 100 mV typ. current sense voltage drop ■ PWM dimming ■ 7% output current accuracy ■ Synchronous rectification ■ ...

Page 2

Contents Contents 1 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

Page 3

LED2000 7.3 Thermal considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

Page 4

List of tables List of tables Table 1. Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

Page 5

LED2000 List of figures Figure 1. Typical application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

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Pin settings 1 Pin settings 1.1 Pin connection Figure 2. Pin connection (top view) DIM 1.2 Pin description Table 1. Pin description Package/pin VFQFPN S08- ...

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LED2000 2 Maximum ratings Table 2. Absolute maximum ratings Symbol V INSW V INA V DIM TOT stg 3 Thermal data Table 3. Thermal data Symbol R thJA ...

Page 8

Electrical characteristics 4 Electrical characteristics T =25 °C, V =12 V, unless otherwise specified Table 4. Electrical characteristics Symbol Operating input voltage range V IN Device ON level Device OFF level V Feedback voltage pin ...

Page 9

LED2000 5 Functional description The LED2000 is based on a “peak current mode” architecture with fixed frequency control consequence, the intersection between the error amplifier output and the sensed inductor current generates the control signal to drive the ...

Page 10

Functional description and the device is enabled. The pre-regulator block supplies the BandGap cell with a pre- regulated voltage that has a very low supply voltage noise sensitivity. 5.2 Voltage monitor An internal block continuously senses the V good, the ...

Page 11

LED2000 Table 5. Uncompensated error amplifier characteristics (continued) Description The error amplifier output is compared with the inductor current sense information to perform PWM control. 5.5 Thermal shutdown The shutdown block generates a signal that disables ...

Page 12

Application notes 6 Application notes 6.1 Closing the loop Figure 5. Block diagram of the loop PWM control Current sense PWM comparator 6.2 G (s) control to output transfer function CO The accurate control to output transfer function for a ...

Page 13

LED2000 Equation ----------------------------------- - Z ESR C OUT Equation ------------------------------------------- LOAD OUT where: Equation ------ - ...

Page 14

Application notes Figure 6. Transconductance embedded error amplifier and C introduce a pole and a zero in the open loop gain system stability but it is useful to reduce the noise at the ...

Page 15

LED2000 The embedded compensation network is R considered as negligible. The error amplifier output resistance is 240 M singularities are: Equation kHz Z 6.4 LED small signal model Once the system reaches the working condition, ...

Page 16

Application notes Figure 7. Equivalent series resistor [A] 0.1 Figure 8 shows the equivalent circuit of the LED constant current generator. Figure 8. Load equivalent circuit As a consequence, the LED equivalent circuit gives the voltage with the high impedance ...

Page 17

LED2000 Equation ---------------------------------------------------------------- - LED LED n LED 6.5 Total loop gain In summary, the open loop gain can be expressed as: Equation Example 1 Design specification: V =12 V, ...

Page 18

Application notes Figure 9. Module plot Figure 10. Phase plot The cut-off frequency and the phase margin are: Equation 100 kHz C 6.6 Dimming operation The dimming input disables the switching activity, masking the PWM comparator output. ...

Page 19

LED2000 Figure 11. Dimming operation example In fact, when dimming enables the switching activity, a small capacitor value is fast charged with low inductor value consequence, the LEDs current rising edge time is improved and the inductor current ...

Page 20

Application notes Figure 12. LED current falling edge operation 6.6.1 Dimming frequency vs. dimming depth As seen in Section system bandwidth (T The dimming performance depends on the minimum current pulse shape specification of the final application. The ideal minimum ...

Page 21

LED2000 Figure 13. Dimming signal For example, assuming a 1 kHz dimming frequency the maximum dimming depth is 5% or, given a 2% dimming depth, it follows a 200 Hz maximum f The LED2000 dimming performance is strictly dependent on ...

Page 22

Application information The software calculates external components according to the internal database also possible to define new components and ask the software to use them. Bode plots, estimated efficiency and thermal performance are provided. Finally, the user can ...

Page 23

LED2000 Figure 15. Equivalent circuit The LED ripple current can be calculated as the inductor ripple current ratio flowing into the output impedance using the Laplace transform (see Equation 23 I RIPPLE where the term 8/ a triangular shape) and ...

Page 24

Application information Equation 27 I s=j RIPPLE Example (see Section Example V = =700 mA, IN LED A lower inductor value maximizes the inductor current slew rate for better dimming performance. Equation 26 Equation ------------ ...

Page 25

LED2000 equivalent RMS current is equal to I are: Equation 30 V OUT D = --------------------------------------- MAX V INMIN and Equation OUT D = ---------------------------------------- - MIN V – INMAX where V is the free-wheeling diode forward ...

Page 26

Application information 7.2 Layout considerations The layout of switching DC-DC converters is very important to minimize noise and interference. Power-generating portions of the layout are the main cause of noise and so high switching current loop areas should be kept ...

Page 27

LED2000 7.3 Thermal considerations The dissipated power of the device is tied to three different sources: ● Conduction losses due to the R Equation RDSON_HS OFF RDSON_LS where D is the duty ...

Page 28

Application information V = FW_LED The typical output voltage is: Equation OUT LED R has a typical value and R DSON_HS For the calculation we can estimate R consequence of ...

Page 29

LED2000 The inductor current ripple during ON and OFF phases can be written as: ● ON phase Equation – IN ------------------------------------------------------------------------------------------------------- TON ● OFF phase Equation 41 – V OUT ---------------------------------------------------------------------------------------------- - T ...

Page 30

Application information of the minimum conduction time of the power element. If the hiccup current level (6.2 A typical) is triggered, the switching activity is prevented for 12 cycles. Figure 18 shows the operation of the constant current protection when ...

Page 31

LED2000 Table 8. Component list Reference Figure 20. PCB layout (component side) DFN package Part number GRM31CR61E106KA12L GRM21BR71E225KA73L ERJ14BSFR15U XAL6060-223ME (size 6.36 x 6.56 x 6.1 mm) Doc ID 023432 Rev 3 Application ...

Page 32

Application information Figure 21. PCB layout (bottom side) DFN package Figure 22. PCB layout (component side) SO-8 package It is strongly recommended that the input capacitors are to be put as close as possible to the pins, see C1 and ...

Page 33

LED2000 Figure 23. PCB layout (bottom side) SO-8 package Doc ID 023432 Rev 3 Application information 33/40 ...

Page 34

Typical characteristics 8 Typical characteristics Figure 24. Soft-start Figure 26. Dimming operation Figure 28. LED current falling edge 34/40 Figure 25. Load regulation Vin 12V Vled 7V AM12913v1 Figure 27. LED current rising edge a AM12915v1 Figure 29. Hiccup current ...

Page 35

LED2000 Figure 30. Efficiency vs. IOUT (VIN 32 V) Figure 31. Thermal shutdown protection 9 Ordering information Table 9. Ordering information Order code LED2000PUR LED2000DR 130 ns typ. AM12919v1 Package VFQFPN 4x4 8L SO-8BW Doc ID 023432 Rev 3 Ordering ...

Page 36

Package mechanical data 10 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ® ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available ...

Page 37

LED2000 Figure 32. VFQFPN8 (4x4x1.08 mm) package dimensions Table 11. SO-8 mechanical data Dim ccc mm Min. Typ. 0.10 1.25 0.28 0.17 4.80 4.90 5.80 6.00 3.80 ...

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Package mechanical data Figure 33. SO8 package dimensions 38/40 Doc ID 023432 Rev 3 LED2000 0016023_Rev_E ...

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LED2000 11 Revision history Table 12. Document revision history Date 11-Jul-2012 27-Jul-2012 16-Oct-2012 Revision 1 Initial release. 2 Document status promoted form preliminary to production data. 3 Figure 22 and Figure 23 Doc ID 023432 Rev 3 Revision history Changes ...

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... Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. ...

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