Texas Instruments TPS61390 85VOUT Boost Converters
Texas Instruments TPS61390 85VOUT Boost Converters are fully integrated, with an 85V FET to convert a low input voltage to a higher voltage for biasing the APD. The devices support an input voltage ranging from 2.5V to 5.5V and operate at a 700kHz pulse-width modulation (PWM) crossing the whole load range.
The TPS61390 can accurately mirror the APD current ranging from 0.5uA to 2mA. There are two ratio options for the current proportional to APD current: the MON1 (4:5) and MON2 (1:5). By connecting a resistor from the mirror output (MON1 or MON2) to GND, the current flowing through the APD is converted into the voltage crossing the resistor from MON1/MON2 to GND. Allowing the sample/hold circuitry that is built-in and triggered by an external sampling clock, the current mirror signal (voltage) is transferred and stored on the holdup capacitor. This feature enables the voltage on the holdup capacitor to pass over to an operational amplifier's output.
An external ADC can sense the voltage of the output of the operational amplifier to measure the optical intensity. High-power optical protection is also integrated by clamping the pre-set current limit (programmed by the ISHORT resistor). The response time of the high optical power is typically 0.5µs. The device could recover automatically when the high optical power is removed.
The Texas Instruments TPS61390 is available in a 3mm × 3mm QFN package with the operating junction temperature covering from -40°C to +125°C.
Features
- 2.5V to 5.5V input voltage range
- Output voltage range of up to 85V
- 0.9Ω R(DS)on of switching FET
- 1000mA switch current limit
- Sample window with minimum 400ns
- High optical power protection with 0.5µs response time
- 700kHz switching frequency
- Quiescent current of 110µA from VIN, 340µA from VOUT, 140µA from AVCC
- 4.8ms soft-start time
- 3mm × 3mm × 0.75mm QFN package
Applications
- APD bias
- Optical line terminal
- High-voltage sensor supply
Typical Application Circuit
