a3131 general features
The a3131 is a universal DSP-based PFC solution with Switching-mode Power Supply to
be used in applications requiring power factor values close to unity and highly efficient DC
power supply. Typical application areas for the a3131 are high-power DC motor controllers
and lighting systems. The power factor controller (PFC) is based on the boost topology
and is fully software-controlled. The PFC algorithm is loaded from an on-chip non-volatile
memory for stand-alone operation or can be uploaded to the DSP core using a two-wire
interface.
The switching-mode power supply controller (SMPSC) is based on the flyback topology
with current feedback, and its role is to provide supply voltage(s) for any low-voltage
electronics. Due to its immediate response, the current feedback topology makes the
a3131 especially attractive for systems in which relatively high swings of the AC line
voltage are expected.
Highlights:
PFC
Fully reconfigurable digitally-controlled power factor controller in CMOS
technology
On-chip AC-phase-locked sinusoidal 45...65Hz oscillator to improve AC-line
noise rejection
High accuracy through on-chip 10bit ADC and dedicated RISC processor
Achievable high efficiency (>95%) and power factor (>0.99)
Broad range of user-selectable PWM frequency (5kHz...200kHz)
Low EMC filter requirements due to use of spread-spectrum PWM
Two-wire interface to load software
Supports 90V...135V and 195V...275V 60/50Hz mains standards
On-chip PLL with 1% RC reference oscillator to generate 64MHz clock signal
Switching-Mode Power Supply Controller
Current-mode switching power supply controller in CMOS technology
Immediate response to low-frequency AC line swings
Output voltage and current levels determined by external components only
Energy-saving cycle-skipping mode for operation with low levels of output power
On-chip overcurrent and short-circuit protection
On-chip reference voltage source
Available Options:
On-chip gate drivers
On-chip OTP memory for stand-alone operation of PFC
example application schematic
Rect.
AC
R1
M1
DRV1
L1
15V
D1
HV
R6
C1
R7
PFCIC
PFC_VDD=5V
SMPSC_VDD=5V
R2
64MHz PLL
OTP
Memory
(optional)
SDAT
SCLK
1% RC
Oscillator
PFCDRV
LV
D2
T1
R3
C2
15V
M2
DRV2
DSP
Unit
RAM
Measuring
Amplifiers
VAC
VDC
PFCFB
PFCI
Two-wire
Interface
ADC
+
_
20..100kHz
PWM
+
_
CF
+
_
COMP
V
REF
VF
R8
CMP
AGND
R9
R
COMP
R10
R5
R4
C
COMP
a3131 simplified application schematic (biasing details not shown)
stm32/stm8
