Automotive Linear Voltage Regulator LDO TLF4277-2LD for Active Antenna Supplies: reverse polarity protection

Open online SPICE simulator circuit link: atv_LDO_TLF4277-2LD_v1p1_reverse_polarity.TSC

Low Drop Out Linear Voltage Regulator TLF4277-2LD
Protection Features: Reverse polarity protection

The resistor divider for a specific output voltage can
be calculated as follows:
VQ = ((R1+R2)/R2)*Vref_int
therefore R1 = ((VQ/Vref_int)-1)*R2
For this model, Vref_int = 1.2 V and R2 < 27 kΩ

For VQ_max = 20 V and R1_max = 9*R2_max
therefore R1_max < 243 kΩ

The typical value of Vref_int is specified as typical 1.19 V in
the datasheet, but should be tweaked to actual simulated
value in the design parameters for accurate results.

Thermal model description:
Thermal Model = 4: JEDEC 1s0p, 600mm2 cooling area
Thermal Model = 5: JEDEC 1s0p, footprint
Thermal Model = 6: JEDEC 2s2p
Thermal Model = 7: No self-heating, only TEMP value used as temperature

Model performance:
- dynamic behavior partially modelled
- loop behavior is idealized
- the thermal simulations represent an approximation of the actual thermal
behavior of the device according to the JEDEC standards at Power = 2.55 Watts
and Temperature = 85 °C

The TLF4277-2LD is the ideal companion IC to supply active antennas for car
infotainment applications. The adjustable output voltage makes the TLF4277-2LD
capable of supplying the majority of standard active antennas such as: FM/AM,
DAB, XM and SIRIUS.

The TLF4277-2LD is a monolithic integrated low drop out voltage regulator
capable of supplying loads up to 300 mA. TLF4277-2LD provides an adjustable
output voltage in a range from 5 V up to 12 V. The integrated current
monitor function is a unique feature that provides diagnosis and system
protection functionality.

Via the enable function the IC can be disabled to lower the power consumption.