Spansion
®
Analog and Microcontroller
Products
The following document contains information on Spansion analog and microcontroller products. Although the
document is marked with the name “Fujitsu”, the company that originally developed the specification, Spansion
will continue to offer these products to new and existing customers.
Continuity of Specifications
There is no change to this document as a result of offering the device as a Spansion product. Any changes that
have been made are the result of normal document improvements and are noted in the document revision
summary, where supported. Future routine revisions will occur when appropriate, and changes will be noted in a
revision summary.
Continuity of Ordering Part Numbers
Spansion continues to support existing part numbers beginning with “MB”. To order these products, please use
only the Ordering Part Numbers listed in this document.
For More Information
Please contact your local sales office for additional information about Spansion memory, analog, and
microcontroller products and solutions.
FUJITSU SEMICONDUCTOR
DATA SHEET
DS04-27204-6E
ASSP
BIPOLAR
SWITCHING REGULATOR
CONTROLLER
MB3775
■
LOW VOLTAGE DUAL PWM SWITCHING REGULATOR CONTROLLER
The MB3775 is a dual pulse-width-modulation control circuit. It contains the basic circuits required for two PWM
control circuits. Complete synchronization is obtained by using the same oscillator output waveform.
This IC can provide following types of output voltage: step down, step up, and inverter. Power consumption is low,
thus the MB3775 is ideal for use in high-efficiency portable equipment.
■
FEATURES
•
•
•
•
•
•
•
•
Wide supply voltage range: 3.6 V to 18 V
Low current consumption: 1.3 mA typical
Wide oscillation frequency range: 1 kHz to 500 kHz
On-chip timer latch short protection circuit
On-chip under voltage lockout protection
On-chip reference voltage: 1.28 V
Variable dead time provides control over total operating range.
Two types of packages (SOP-16pin : 1 type, SSOP-16pin : 1 type)
■
APPLICATIONS
• LCD monitor/panel
• Surveillance camera
etc.
Copyright©1994-2010 FUJITSU SEMICONDUCTOR LIMITED All rights reserved
2010.9
MB3775
■
PIN ASSIGNMENT
(TOP VIEW)
C
T
R
T
+IN1
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
REF
SCP
+IN2
-
IN1
FB1
D.T.C.1
OUT1
E/GND
-
IN2
FB2
D.T.C.2
OUT2
V
CC
(FPT-16P-M06)
(FPT-16P-M05)
2
DS04-27204-6E
MB3775
■
PIN DESCRIPTION
No.
1
2
3
4
5
Pin
C
T
R
T
+IN1
−IN1
FB1
Function
Oscillator timing capacitor pin (150 pF to 15,000 pF) .
Oscillator timing resistor pin (5.1 kΩ to 100 kΩ) .
Error amplifier 1 non-inverted input pin.
Error amplifier 1 inverted input pin.
Error amplifier 1 output pin.
A resistor and a capacitor are connected between this pin and the
−IN1
pin to adjust gain and
frequency.
OUT1 dead-time control pin.
Dead-time control is adjusted by an external resistive divider connected to the V
REF
pin.
A capacitor connected between this pin and GND enables soft-start operation.
Open collector output pin.
Output transistor has common ground independent of signal ground.
This output can source or sink up to 50 mA.
Power supply pin (3.6 V to 18 V)
Open collector output pin.
Output transistor has common ground independent of signal ground.
This output can source or sink up to 50 mA.
Sets the dead-time of OUT2.
The use of this pin is the same as that of DTC1.
Error amplifier 2 output pin.
A resistor and a capacitor are connected between this pin and the -IN2 pin to adjust gain and
frequency.
Error amplifier 2 inverted input pin.
Error amplifier 2 non-inverted input pin.
The time constant setting capacitor connection pin of the timer latch short-circuit
protection circuit.
Connects a capacitor between this pin and GND.
For details, see “■ HOW TO SET TIME CONSTANT FOR TIMER LATCH SHORT-CIRCUIT
PROTECTION CIRCUIT”.
1.28 V reference voltage output pin which can be obtained up to 1 mA.
This pin is used to set the reference input and idle period of the error amplifiers.
6
DTC1
7
8
9
10
OUT1
E/GND Ground pin.
V
CC
OUT2
11
DTC2
12
13
14
FB2
−IN2
+
IN2
15
SCP
16
V
REF
DS04-27204-6E
3
MB3775
■
BLOCK DIAGRAM
9
V
REF
= 1.28 V
V
CC
1.9 V
1.3 V
+
−
−
1
2
16
Reference
Voltage
2.5 V
Triangular
Waveform
OUT 1
7
Error Amp 1
3
4
5
12
14
13
+
−
PWM Comp.1
S.C.P.Comp.
+
+
−
+
−
−
OUT 2
PWM Comp.2
10
1.1 V
Error Amp 2
+
−
2.5 V
15
1
μA
S
R
R
1.28 V
0.9 V
0.9 V
Latch
U.V.L.O.
+
+
−
D.T.C.Comp.
GND
1.8 V
6
11
8
4
DS04-27204-6E
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