FP6296-10A Current Mode Non-Synchronous PWM Boost Converter에 대한 고찰

 

 

 

오늘은 FP6296-10A Current Mode Non-Synchronous PWM Boost Converter에 대한 고찰을 해 보겠습니다.

FP6296은 DCDC Boost Converter로 아래와 같은 특성을 지니고 있습니다.

 

내부 Switching Current가 10A로서, 1 Cell Li-Ion Battery 입력을 사용해서 12V/1.5A까지는 충분히 출력을 내는 IC입니다.

요즘 많이 사용하는 1cell Battery System으로서 9V~12V용 Motor를 구동시키는 경우는 사용하기 편리합니다. 

 

The FP6296 is a current mode boost DC-DC converter. It is PWM circuitry with built-n 15mΩ power MOSFET make this regulator highly power efficient.

The non-inverting input of error amplifier connects to a 1.2V precision reference voltage.

Current mode control and external compensation network make is easy and flexible to stabilize the system.
The FP6296 is available in the SOP-8L(EP) package to fit in space-saving PCB for the application fields.

 

 

 

• Supply Voltage Operating Range: 2.7V to 12V

• Adjustable Output up to 13V

• Internal Fixed PWM frequency: 400KHz

• Precision Feedback Reference Voltage: 1.2V (±2%)

• Internal 15mΩ, 10A, 14V Power MOSFET

• Shutdown Current: 1μA (Max.)

• Over Temperature Protection

• Internal Soft Start Function

• Adjustable Over Current Protection: 2A ~ 10A

• Package: SOP-8L(EP)

 

Function Description

Operation
The FP6296 is a current mode boost converter. 

The switching frequency is 400KHz and operates with pulse width modulation (PWM). 

Build-in 14V / 10A MOSFET provides a high output voltage.

The control loop architecture is peak current mode control; therefore slope compensation circuit is added to the current signal to allow stable operation for duty cycles larger than 50%.

 

Current Limit Program
A resistor between OC and GND pin programs peak switch current. 

The resistor value should be between 150k to 51kΩ. The current limit will be set from 2A to 10A. 

Keep traces at this pin as short as possible. Do not put capacitance at this pin.

 

 

Over Temperature Protection (OTP)
FP6296 will turn off the power MOSFET automatically when the internal junction temperature is over 150°C. 

The power MOSFET wake up when the junction temperature drops 20°C under the OTP threshold temperature.

 

Enable Mode / Shutdown Mode
Drive the EN pin to ground to shutdown the IC. 

Shutdown mode forces to turn off all internal circuitry, and reduces the HVDD supply current to 1uA (max). 

The EN pin rising threshold is 1.1V.

 

 

 

Application Information

Inductor Selection
Inductance value is decided based on different condition. 

3.3uH to 10μH inductor value is recommended for general application circuit. 

There are three important inductor specifications, DC resistance, saturation current and core loss. 

Low DC resistance has better power efficiency.

 

Capacitor Selection
The output capacitor is required to maintain the DC voltage. 

Low ESR capacitors are preferred to reduce the output voltage ripple. 

Ceramic capacitor of X5R and X7R are recommended, which have low equivalent series resistance (ESR) and wider operation temperature range.

 

Diode Selection
Schottky diodes with fast recovery times and low forward voltages are recommended. 

Ensure the diode average and peak current rating exceed the average output current and peak inductor current. In
addition, the diode’s reverse breakdown voltage must exceed the output voltage.

 

Output Voltage Programming
The output voltage is set by a resistive voltage divider from the output voltage to FB.

 

 

 

아래 사진은 Application Demo Board입니다.

 

Vin=3V, Vout=12V, Iout=1A 

Frequency=370kHz, Efficiency=87.5%
Output Ripple=210mV, Temperature IC1=60℃, L1=57℃, D1=60℃

 

 

 

아래는 spec sheet의 응용 회로도입니다.

 

 

 

 

PCB Layout Considerations. 
1. The power traces, consisting of the GND trace, the LX trace and the VIN trace should be kept short, direct and wide.
2. LX、L1 and D1 switching node, wide and short trace to reduce EMI.
3. The resistive divider R1 and R2 must be connected to FB pin directly as closely as possible.
4. FB is a sensitive node. Please keep it away from switching node, LX.
5. The GND of the IC, CIN and COUT should be connected close together directly to a ground plane.
6. The ground of COUT should be connected close and together directly to IC’s GND pin.

 

 

 

fp6296v060-g1.pdf

0.61MB