Tag Archive: diy

My H-Bridge consume 3ma@3.3v when there is no load and both inputs are zero,

    How can i reduce it ?
    my goal is <100uA
Q2 and Q8 are SS8550 and Q3 and Q9 are SS8050, other Qs are 2N2222A


Microlab ATX 400w KA7500 Power supply micro lab 400watt atx ka7500 lm339 2sc2625 st3040 st1020 sbl2040 microlab atx 400w 2sc5027 fr107 2sc5344y atx tamir şema atx smps circuit, atx smps repair schema.


Mosfet load board IRFP450

Three mosfets in parallel provide an adjustable load. Current is sensed with low side resistor. Reference is provided externally (DAC or pot).
Input voltage and current are fed into a PGA which is sent off board.
There is also an 8-bit i2c i/o expander and 18-bit i2c ADC available.


Main components:

  • TO-247 mosfet (IRFP450)
  • TO-220 current sense resistor (35W 0.01Ω)
  • 2ch programmable gain amplifier (MCP6S22)
  • i2c 18-bit ADC (MCP3422)
  • i2c i/o expander (SX1505)



A very simple with a compact design FM stereo decoder schematic circuit can be designed using the TDA7388 IC manufactured by ST Microelectronics .
The TDA7338 is a monolithic integrated stereo decoder with noise blanking for FM car radio applications.
With the used BICMOS technique, the 19KHz Notch Filter, the PLL Filter and Phase Filter is realized on the chip with a Switched Capacitor concept.
The TDA7338 stereo decoder contains all necessary functions for processing the MPX signal.
The only external component needed for the PLL is the ceramic resonator for the oscillator which runs at 456kHz.

The pilot detector output is designed as an open collector output, therefore an external pull up resistor is needed. To force the decoder to “MONO” Pin 19 has to be clamped to a voltage below 0.8V.
Selecting VCO-OFF (Pin 7 to GND) the VCO is switched off and the SB and HCC are disabled.
This TDA7338 receiver circuit needs to be powered by a 9 volts DC power supply .