12V Automotive LED synchronous H-Bridge topology with LITIX™ Power controller TLD5190 (Soft Start PWM Dimming)

Open online SPICE simulator circuit link: atv_12v_LED_lighting_full-bridge_controller_TLD5190_pwm_dimming_V3.tsc

12V Automotive LED synchronous H-Bridge topology with LITIX™ Power controller TLD5190 (Soft Start PWM Dimming)

The TLD5190QV is a synchronous MOSFET H-Bridge DC/DC controller with built
in protection features. This concept of a synchronous and seamless buck-boost
regulation provides a very efficient solution for circuits where the output (load)
voltage is on the same level as the input voltage, e.g. in short chains with 2 to 3
high power LEDs or laser diodes connected to a 12 V electrical system.

This test bench shows the following features:
• Soft start: capacitors connected to SOFT_START and COMP inputs are chosen in
order to see the impact of soft start in the start-up until the circuit reaches steady-state.
If charging ramp at COMP pin is faster than ramp at SOFT_START pin and they move
away by more than 0.7 V, then the ramp at COMP pin will be limited.
• Output current control via SET pin (analog dimming): RFB is set to 150 mΩ in order to
have 1 A at the output. SET pin is decreased from 1.4 V (100% analog dimming) to
0.8 V (50% analog dimming).
• Output current control via PWMI pin (digital dimming): when PWMI pin is set to logic
low, the output current will drop to 0 A and the output capacitor starts to discharge
(digital dimming).

Notes:
BODY_DIODE is not a real diode but a Voltage Controlled Current Source which
models the threshold and ON/OFF states resistance. RCOMP is a placeholder for
further adjustment of the resistor for stability purpose. Keep unchanged otherwise.
S2G is a virtual pin used for monitoring short to ground fault if VFB<0.563V for at
least 8 clock cycles. During start-up, the detection is ignored until
VSOFT_START>1.75V.

- Change simulation time:
"Analysis->Transient: Start - End Display"
- Double click on the green window to enter design criteria
- Click on "Run" and Simulate Transient