AMC3842B/43B/44B/45B
www.addmtek.com
DESCRIPTION
The AMC3842B/43B/44B/45B are fixed frequency
current-mode PWM controllers specially designed for
OFF-Line switching power supply and DC-to-DC converters
with a minimum number of external components. These
devices feature a trimmed oscillator for precise duty cycle
control, a temperature compensated reference, high gain error
amplifier, current sensing comparator, and high current totem
pole output which is suitable for driving MOSFETs.
The under voltage lock-out (U.V.L.O.) is designed to
operated with 200µA start-up current in typical, allowing an
efficient bootstrap supply voltage design. The U.V.L.O.
thresholds for the AMC3842B/44B are 16V (on) and 10V
(off), which are ideal for off-line applications. The
corresponding typical threshold for the AMC3843/45BB is
8.4V (on) and 7.6V (off). The AMC3842B/43B can operate
within 100% duty cycle and the AMC3844B/45B can operate
within 50% duty cycle.
APPLICATIONS
Off-line flyback or forward converters.
DC-to-DC buck or boost converter.
Monitor Power Supply
C
URRENT
M
ODE
PWM C
ONTROLLER
FEATURES
Low Start-Up current (max. 200µA)
Optimized for Off-Line and DC-to-DC
Converters
Maximum Duty Cycle
U.V.L.O. with Hysteresis
Operating Frequency Up to 500KHz
Internal Trimmed Bandgap Reference
High Current Totem Pole Output
Error Amplifier With Low Output Resistance
Available in 8-Pin Plastic DIP and Surface
Mount 14-Pin S.O.I.C.
Identical pin assignment to earlier UC384X
series.
PACKAGE PIN OUT
COMP
V
FB
I
SENSE
R
T
/C
T
V
REF
V
CC
OUTPUT
GND
8-Pin Plastic DIP
(Top View)
AVAILABLE OPTIONS
Device
AMC3842B
AMC3843B
AMC3844B
AMC3845B
Start-UP
Voltage
16V
8.4V
16V
8.4V
Max. Duty
Hysteresis
Cycle
6V
0.8V
6V
0.8V
< 100%
< 100%
< 50%
< 50%
COMP
NC
V
FB
NC
I
SENSE
NC
R
T
/C
T
V
REF
NC
V
CC
V
C
OUTPUT
GND
PWR
R
T
/C
T
COMP
V
FB
I
SENSE
V
REF
V
CC
OUTPUT
GND
14-Pin Plastic S.O.I.C.
Surface Mount
(Top View)
8-Pin Plastic S.O.I.C.
Surface Mount
(Top View)
T
A
(
O
C)
0 to 70
0 to 70
Note:
ORDER INFORMATION
Plastic DIP-8
Plastic SO-14
M
8-pin
D
14-pin
AMC384XBM
AMC384XBD
AMC384XBM (Lead Free)
AMC384XBD (Lead Free)
DM
8-pin
Plastic SO-8
AMC384XBDM
AMC384XBDM (Lead Free)
1. All surface-mount packages are available in Tape & Reel.
AMC384XBDMT).
2. The letter ”F” is marked for Lead Free process.
1
Append the letter “T” to part number (i.e. AMC384XBDT, or
Copyright
©
2006 ADDtek Corp.
DD019_F -- OCTOBER 2006
ADDTEK [ ADDTEK CORP ]
