Nov SP6126 High-Voltage, Step Down Controller in TSOT6 GND LX FB FEATURES 6 5 4 Wide 4.5V 29V Input Voltage Range Internal Compensation Built-in High Current PMOS Driver Adjustable Overcurrent Protection SP6126 Internal soft-start 6 PinTSOT 600kHz Constant Frequency Operation 0.6V Reference Voltage 1% output setpoint accuracy 1 2 3 Lead Free, RoHS Compliant Package: VIN VDR GATE Small 6-Pin TSOT DESCRIPTION The SP6126 is a PWM controlled step down (buck) voltage mode regulator with VIN feedforward and internal Type-II compensation. It operates from 4.5V to 29V making is suitable for 5V, 12V, and 24V applications. By using a PMOS driver, this device is capable of operating at 100% duty cycle. The high side driver is designed to drive the gate 5V below VIN. The programmable overcurrent protection is based on high-side MOSFETs ON resistance sensing and allows setting the overcurrent protection value up to 300mV threshold (measured from VIN-LX). The SP6126 is available in a space-saving 6-pin TSOT package making it the smallest controller available capable of operating from 24VDC supplies. TYPICAL APPLICATION CIRCUIT VIN C1 Q1 10uF 12V Si2343DS 2 1 Gate GND Vin L1, IHLP-2525CZ Rs=1k 6.8uH, 60mOhm, 4.5A VOUT LX C7 0.1uF 6 C4 3.3V SP6126 Ds RZ 22uF 0-2.0A 3 MBRA340T3G 2K VDR R1 200k, 1% CZ 4 62pF GND VFB GND R2 5 44.2k, 1% D1 1N4148 SHDN High=Of f Nov07-08 RevG SP6126: TSOT-6 PFET Buck Controller 2008 Exar Corporation 1 ABSOLUTE MAXIMUM RATINGS These are stress ratings only, and functional operation of Input Voltage.................................................-0.3V to 30V the device at these ratings or any other above those Lx.-2V to 30V indicated in the operation sections of the specifications FB..................................................-0.3V to 5.5V below is not implied. Exposure to absolute maximum rating Storage Temperature.....-65 C to 150 C conditions for extended periods of time may affect Junction Temperature...................................-40C to 125C reliability. Lead Temperature (Soldering, 10 sec)....300 C ESD Rating..1kV LX, 2kV all other nodes, HBM ELECTRICAL SPECIFICATIONS Specifications are for T =T =25C, and those denoted by apply over the full operating range, -40C< T <125C. Unless AMB J j otherwise specified: VIN =4.5V to 29V, CIN = 4.7F. PARAMETER MIN TYP MAX UNITS CONDITIONS UVLO Turn-On Threshold 4.2 4.35 4.5 V 0C< T <125C j UVLO Turn-Off Threshold 4.0 4.2 4.4 V 0C< T <125C j UVLO Hysterisis 0.2 V Operating Input Voltage 4.5 29 V 0C< T <125C j Range Operating Input Voltage 7 29 V Range Operating VCC Current 0.3 3 mA VFB=1.2V Reference Voltage Accuracy 0.5 % Reference Voltage Accuracy 0.5 2 % Reference Voltage 0.6 V Reference Voltage 0.588 0.6 0.612 V Switching Frequency 510 600 690 kHz Peak-to-peak ramp Modulator VIN/5 V Minimum ON-Time Duration 40 100 ns Minimum Duty Cycle 0 % Maximum Duty Cycle 100 % Gate Driver Turn-Off Internal resistor between GATE and 50 60 k Resistance VIN Gate Driver Pull-Down VIN=12V, V =0.5V, Measure FB 4 8 Resistance resistance between GATE and VDR Gate Driver Pull-up VIN=12V, V =0.7V, Measure FB 3 6 Resistance resistance between GATE and VIN VIN - VDR voltage difference 4.5 5.5 V Measure VIN VDR, VIN>7V Overcurrent Threshold 270 300 330 mV Measure VIN - LX LX pin Input Current 25 30 35 uA V = VIN LX OFF interval during hiccup 100 ms VFB=0.58V, measure between Soft start time 3 5 9 ms VIN=4.5V and first GATE pulse SHDN Threshold 0.9 1.0 1.1 V Apply voltage to FB SHDN Threshold Hysteresis 100 mV Nov07-08 RevG SP6126: TSOT-6 PFET Buck Controller 2008 Exar Corporation 2