Texas Instruments UCD3138 User Manual

Idle
Relay
close
Ramp up
PFC
on
PFC
hiccup
PFC shutdown
and
latch
Vin > 90V
after
100ms
Vout = 390V
Vout >420V
Vout
<
380
V
Vout
>
420 V
Vout >435V
Vin
<
85 V
www.ti.com Digital PFC Description
12.5 State Machine
The PFC hiccups once an over-voltage condition is detected. Only very serious over voltage causes PFC
shut down and latch.
Figure 37 is the PFC state machine diagram shown below.
Figure 37. PFC State Machine
12.6 PFC Control Firmware
The PFC Control Firmware is almost all implemented in the IRQ function, which includes:
• ADC measurement
• State machine
• V
RMS
calculation
• Voltage loop calculation
• Current reference calculation
• AC drop detection
• UART receive data
• Frequency dithering
• ZVS control
39
SLUU885B–March 2012–Revised July 2012 Digitally Controlled Single-Phase PFC Pre-Regulator
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Texas Instruments UCD3138 Specifications

General

Brand	Texas Instruments
Model	UCD3138
Category	Power Supply
Language	English