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Description
GM384XA series is high performance with fixed-frequency
current mode PWM controllers. They are specially de-
signed for off-Line and DC-to-DC converter applications.
They require minimal external components to precisely tai-
lor performance in a wide variety of applications.
GM384XA series includes a trimmed oscillator for precise
duty cycle control, a temperature-compensated reference,
high gain error amplifier, a current-sensing comparator,
and a high-current totem pole output for driving a power
MOSFET.
On-chip protection features include undervoltage lockouts
with hysteresis for both input and reference, cycle-by-cycle
current limiting, programmable output deadtime, and a
latch for single pulse metering. All these are in a simple
DIP-8 or SOP-8 package!
GM3842A and GM3844A have UVLO thresholds of 16V
(on)/10V(off); GM3843A and GM3845A have UVLO thresh-
olds of 8.4V (on)/ 7.6V (off). GM3842A and GM3843A oper-
ate within 100% duty cycle; GM3844A and GM3845A oper-
ate within 50% duty cycle.
Features
Low Start-Up and Operating Current
Automatic Feed Forward Compensation
Current Mode Operating Frequency up to
500kHz
Trimmed Oscillator Discharge Current for
Precise Duty Cycle Control
Latching PWM for Cycle-By-Cycle Current
Limiting
Undervoltage Lockout with Hysteresis
High Current Totem Pole Output
The GM384XA Have Start-up Current 0.17mA
SIMPLIFIED BLOCK DIAGRAM
Vref 8
RT/ CT 4
Voltage Feedback Input 2
Output Compensation 1
5.0V
REFERENCE
R
R VREF
Undervoltage
LOCKOUT
VCC
7
VCC
Undervoltage
LOCKOUT
OSCILLATOR
Error
Amplifier
+
-
Latching
PWM
5
GND
7 VC
6 Output
5 Power Ground
3 Current Sense Input
www.gammamicro.com 1
MARKING INFORMATION & PIN CONFIGURATIONS (TOP VIEW)
SOP - 8
VCC
VREF
OUTPUT
GND
8765
GM384X
Ayww
1234
COMP
FB
RT / CT
ISENSE
DIP - 8
VCC
VREF
OUTPUT
GND
8765
GM384X
Ayww
1234
COMP
FB
RT / CT
ISENSE
A = Assembly Location
Y = Year
W W = Weekly
ORDERING INFORMATION (Green Package Products are available now!)
Ordering Number
Package
GM3842AS8T
SOP - 8
GM3842AS8R
SOP - 8
GM3842AD8T
DIP-8
GM3843AS8T
SOP - 8
GM3843AS8R
SOP - 8
GM3843AD8T
DIP-8
GM3844AS8T
SOP - 8
GM3844AS8R
SOP - 8
GM3844AD8T
DIP-8
GM3845AS8T
SOP - 8
GM3845AS8R
SOP - 8
GM3845AD8T
DIP-8
* For detail ordering number identification, please see last page.
** For green package products, please add " G" at the end of each part number.
Shipping
100 Units/ Tube
2,500 Units/ Tape & Reel
60 Units/ Tube
100 Units/ Tube
2,500 Units/ Tape & Reel
60 Units/ Tube
100 Units/ Tube
2,500 Units/ Tape & Reel
60 Units/ Tube
100 Units/ Tube
2,500 Units/ Tape & Reel
60 Units/ Tube
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