rt8287a Richtek Technology Corporation, rt8287a Datasheet
rt8287a
Available stocks
Related parts for rt8287a
rt8287a Summary of contents
Page 1
... Synchronous Step-Down Converter General Description The RT8287A is a synchronous step-down regulator with an internal power MOSFET. It achieves 4A of continuous output current over a wide input supply range with excellent load and line regulation. Current mode operation provides fast transient response and eases loop stabilization. ...
Page 2
... Function Pin Description Pin No. Pin Name 1 VIN BOOT PGOOD 10 SS www.richtek.com VIN BOOT IN RT8287A PGOOD VCC C C 47nF AGND GND 14 12, 13, 15 (Exposed Pad) Table 1. Recommended Components Selection R2 (kΩ 14. ...
Page 3
... Analog Ground. Connect this pin to the system ground in PCB layout. Shutdown Ramp Generator Regulator V A Oscillator V C 500kHz Lockout Reference + Error - Amplifier + + - V C 30pF 400k 10µA 1pF RT8287A Pin Function Current Sense Amplifier - + Driver + R - PWM Comparator BOOT SW GND www.richtek.com 3 ...
Page 4
... RT8287A Absolute Maximum Ratings ----------------------------------------------------------------------------------- −0.3V to 26V Supply Input Voltage Switch Voltage, SW ----------------------------------------------------------------------------------------- −0. Boot Voltage, BOOT ----------------------------------------------------------------------------------------- (SW − 0.3V) to (SW + 6V) All Other Pins ------------------------------------------------------------------------------------------------- −0. Power Dissipation 25° WDFN-14L 4x3 ------------------------------------------------------------------------------------------------ 1.667W Package Thermal Resistance (Note 2) WDFN-14L 4x3, θ ------------------------------------------------------------------------------------------ 60°C/W JA WDFN-14L 4x3, θ ...
Page 5
... Note 4. The device is not guaranteed to function outside its operating conditions. DS8287A-01 August 2011 Symbol Test Conditions Sink 4mA V V Rising UVLO IN ΔV UVLO I = 5mA 47nF 25° high-effective thermal conductivity four-layer test board of JEDEC A RT8287A Min Typ Max -- 0 3.8 4 4.2 -- 400 ...
Page 6
... RT8287A Typical Operating Characteristics Efficiency vs. Output Current 100 OUT 0 0 0.5 1 1.5 Output Current (A) Reference Voltage vs. Temperature 0.84 0.83 0.82 0.81 0.80 0.79 0.78 0.77 0.76 -50 - Temperature (°C) Switching Frequency vs. Input Voltage 550 525 500 475 450 425 400 375 350 Input Voltage (V) www ...
Page 7
... Temperature (°C) Load Transient Response V OUT I OUT (2A/Div 12V OUT Time (100μs/Div) Output Voltage Ripple V OUT V LX (10V/Div (2A/Div) Time (1μs/Div) RT8287A V = 12V 1.22V IN OUT 50 75 100 125 = 1.22V OUT V = 12V OUT www.richtek.com 7 ...
Page 8
... RT8287A Power On from (10V/Div) V OUT (1V/Div) V PGOOD (5V/Div (5A/Div 12V Time (5ms/Div) Power On from (5V/Div) V OUT (1V/Div) V PGOOD (5V/Div (5A/Div 12V Time (2.5ms/Div) www.richtek.com (10V/Div) V (1V/Div) V PGOOD (5V/Div) (5A/Div) = 1.22V OUT OUT V (5V/Div) ...
Page 9
... EN pin to adjust IC lockout threshold, as shown in Figure 4. For example output voltage is regulated 100nF from a 12V input voltage, the resistor R to set input lockout threshold larger than 8V. RT8287A enable input. Pulling the EN pin * capacitor from the VIN pin, as can be seen from connected between V ...
Page 10
... PGOOD R3 100k VCC C AGND GND C 14 12, 13, 15 (Exposed Pad VIN BOOT C IN RT8287A PGOOD R3 100k VCC C AGND GND C 14 12, 13, 15 (Exposed Pad) ripple current ΔI with higher inductance. Δ Having a lower ripple current reduces not only the ESR losses in the output capacitors but also the output voltage ripple ...
Page 11
... Capacitance ( best, this ringing can couple to the output IN large enough to damage the between SW and GND and locating but this method will BOOT RT8287A , where I = OUT RMS Case Size 1210 1210 1206 1210 1210 1210 www.richtek.com 11 ...
Page 12
... T is the maximum junction temperature, T J(MAX) the ambient temperature, and JA thermal resistance. For recommended operating condition specifications of the RT8287A, the maximum junction temperature is 125 C and T is the ambient temperature. The junction to ambient A thermal resistance layout dependent. For WDFN- JA 14L 4x3 package, the thermal resistance standard JEDEC 51-7 four-layer thermal test board ...
Page 13
... C IN VIN 14 AGND GND SW GND 3 12 VCC GND C SS BOOT BOOT PGOOD OUT C OUT GND Figure 7. PCB Layout Guide RT8287A GND C SS Place the R2 feedback as close to the possible OUT www.richtek.com 13 ...
Page 14
... RT8287A Outline Dimension Symbol Richtek Technology Corporation Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time ...