FA3675F
FA3675F
CMOS IC
For Switching Power Supply Control
■ Description
FA3675F is a control IC for 6-channel DC-DC converter.
This IC can directly drive a Nch/Pch-MOSFET.
This IC is suitable to reduce converter size because it has
many functions in a small package LQFP-48.
■ Features
• 6-channel PWM control with MOSFET direct driving :
5-channel for Pch-MOSFET, 1channel for Nch-MOSFET
• Low input voltage: 2.5V to 20V
• ±1.0% high accuracy bandgap reference
• Low power consumption by means of CDMOS
Standby mode: 20µA(max.)
Operating mode: 10mA(max.)
• Soft start function for each channel
• ON/OFF function for each channel
• Timer latch for short protection
• Undervoltage lockout
• Wide range of operation frequency: 50kHz to 1MHz
• Package: LQFP-48(Thin and small)
■ Application
• VTR-camera, digital-steel-camera and portable equipment
■ Dimensions, mm
Á LQFP-48
±0.3
9.0
7.0
36 25
48 37
112
0.5
±0.1
0.2
±0.06
1.45 max
±0.3
8.0
7.0
9.0
13 24
7.8
±0.2
0.5
0.10
0.127
0~7˚
±0.06
±0.05
122
■ Block diagram
FA3675F
123
FA3675F
Pin Pin Description
No. symbol
1 VCC1 Power supply for control circuit
2 RT Oscillator timing resistor
3 CT Oscillator timing capacitor
4 CS3 Soft start for Ch. 3 & Ch. 4
5 CS5 Soft start for Ch. 6
6 CS4 Soft start for Ch. 5
7 CS1 Soft start for Ch. 1
8 CS2 Soft start for Ch. 2
9 VREF Reference voltage output
10 CREF Capacitor for reference voltage output
11 VREG Regulated voltage output
12 IN2- Ch. 2 inverting input to error amplifier
13 FB2 Ch. 2 output of error amplifier
14 IN1- Ch. 1 inverting input to error amplifier
15 FB1 Ch. 1 output of error amplifier
16 IN5+ Ch. 5 non-inverting input to error amplifier
17 IN5- Ch. 5 inverting input to error amplifier
18 FB5 Ch. 5 output of error amplifier
19 IN6- Ch. 6 inverting input to error amplifier
20 FB6 Ch. 6 output of error amplifier
21 IN3+ Ch. 3 non-inverting input to error amplifier
22 IN3- Ch. 3 inverting input to error amplifier
23 FB3 Ch. 3 output of error amplifier
24 IN4+ Ch. 4 non-inverting input to error amplifier
Pin Pin Description
No. symbol
25 IN4- Ch. 4 inverting input to error amplifier
26 FB4 Ch. 4 output of error amplifier
27 CP Timing capacitor for timer latch delay
28 GND Ground
29 TLSEL
30 CNT5 Ch. 6 ON/OFF function
31 CNT4 Ch. 5 ON/OFF function
32 CNT2 Ch. 2 ON/OFF function
33 CNT3 Ch. 3
34 CNT1 Ch. 1 ON/OFF function
35 VCC2 Power supply for output stage
36 VDRV Bias for logic circuit of outputs
37 PGND1 Power ground
38 OUT1S Ch. 1 source electrode of output stage
39 OUT1 Ch. 1 output (for Pch-MOSFET)
40 OUT4 Ch. 4 output (for Pch-MOSFET)
41 OUT3 Ch. 3 output (for Pch-MOSFET)
42 OUT2S Ch. 2 source electrode of output stage
43 OUT2 Ch. 2 output (for Pch-MOSFET)
44 OUT6S Ch. 6 source electrode of output stage
45 OUT6 Ch. 6 output (for Nch-MOSFET)
46 OUT5 Ch. 5 output (for Pch-MOSFET)
47 OUT5S Ch. 5 source electrode of output stage
48 PGND2 Power ground
Ch. 3 & Ch. 4 timer latch selection (Low: disable)
& Ch. 4
ON/OFF function
■ Absolute maximum ratings
Item Symbol Rating Unit
Power supply voltage VCC 20.0 V
Source peak current IOUT –200 mA
Sink peak current IOUT 200 mA
Input voltage for analog input VANA –0.3 to +2.5 V
Input voltage for logic input VLOG –0.3 to Vcc +0.5 (Vcc ≤ 5.0V)
–0.3 to +5.5 (Vcc > 5.0V)
Total power dissipation * Pd 550 mW
Junction temperature TJ 125 °C
Ambient temperature TOP –20 to +85 °C
Storage temperature Tstg –40 to +150 °C
V
* Ta < 25°C
■ Recommended operating conditions
Item Symbol Min. Max. Unit
Power supply voltage VCC 2.5 18.0 V
Input voltage for logic input Vcc ≤ 5.0
Vcc > 5.0 0.0 5.25
Oscillation frequency fOSC 50 1000 kHz
Oscillator timing resistor RT 6.8 100 kΩ
Oscillator timing capacitor CT 22 1000 pF
CREF terminal by-pass capacitor CREF 0.01 µF
VLOG 0.0 Vcc +0.25 V
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