Auxiliary Power; Output Stage; Digital Circuit - Chroma 62020H-150S Operating & Programming Manual

Programmable DC Power Supply (with Solar Array Simulation) 62000H Series
Operating & Programming Manual
6.2.2

Auxiliary Power

1. The auxiliary power voltages are generated by sending the AC source input through a
bridge rectifier and a flyback converter to get the desired output voltages.
2. The auxiliary power output provides four voltages: +5V, +16V, ±12V, and +48V.
6.2.3

Output Stage

1. The output stage is a full wave bridge that uses a PWM IC and is controlled in voltage
mode.
2. There are two output modes -- Constant Voltage (CV Mode) and Constant Current (CC
Mode), which switch automatically according to the load state.
In Constant Voltage mode, the IC detecting signal is the Output voltage and the actual
load voltage (remote sense) from the output remote sense line.
In Constant Current mode, the IC detecting signal is the Output current.
3. The secondary side is a one stage LC filter that reduces the ripple voltage and ripple
current.
4. The Dummy load acts as a Constant Current Source. The Dummy load current will be
adjusted based on the output voltage. It will respond if the programmed voltage is less
than the current output. The output has OVP; when it exceeds the OVP voltage (16 bit
DAC) set by the front panel, the output will be disabled.
6.2.4

Digital Circuit

1. The digital circuit control unit is composed of TI's IC with the Lattice FPGA.
2. The 3.3V power source required by the FPGA is derived from +5VD.
3. The 3.3V and 1.26V power sources required by the DSP are derived from +5VD.
4. The analog program interface and digital circuit signals are isolated by the +16VD power
source with a free-running flyback converter and linear regulator.
5. The TTL output is a +5V level and the internal digital signal is a +3.3V level.
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