UC184xA / 284xA / 384xA
CURRENT
MODE PWM CONTROLLER
P
R O D U C T I O N D A T A S H E E T
T
H E
I
N F I N I T E
P
O W E R O F
I N N O V A T I O N
KEY FEATURES
DESCRIPTION
The UC184xA family of control ICs provides externally programmable oscillator to set
all the necessary features to implement off-line frequency and maximum duty cycle. The
fixed-frequency, current-mode switching power undervoltage lock-out is designed to operate with
LOW START-UP CURRENT.
(0.5mA max.)
TRIMMED OSCILLATOR
DISCHARGE CURRENT. (See
Product Highlight)
OPTIMIZED FOR OFF-LINE
AND DC-TO-DC
CONVERTERS.
AUTOMATIC FEED FORWARD
COMPENSATION.
PULSE-BY-PULSE CURRENT
LIMITING.
ENHANCED LOAD RESPONSE
CHARACTERISTICS.
UNDER-VOLTAGE LOCKOUT
WITH HYSTERESIS.
DOUBLE PULSE
SUPPRESSION.
HIGH-CURRENT TOTEM POLE
OUTPUT.
INTERNALLY TRIMMED
BANDGAP REFERENCE.
500KHz OPERATION.
LOW RO ERROR AMPLIFIER.
supplies with
a
minimum of external 250µA typ. start-up current, allowing an efficient
components. The current mode architecture bootstrap supply voltage design. Available
demonstrates improved load regulation, pulse- options for this family of products, such as start-
by-pulse current limiting and inherent protection up voltage hysteresis and duty cycle, are
of the power supply output switch. The IC summarized below in the Available Options
includes: A bandgap reference trimmed to ±1% section. The UC184xA family of control ICs is
accuracy, an error amplifier, a current sense also available in 14-pin SOIC package which
comparator with internal clamp to 1V, a high makes the Power Output Stage Collector and
current totem pole output stage for fast Ground pins available.
switching of power MOSFET's, and an
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
PRODUCT HIGHLIGHT
COMPARISON OF UC384
XA
VS. SG384
X
D
ISCHARGE URRENT
C
UC384xA
SG384x
Min. Limit
SG384x
Max. Limit
T =25 C
A
KEY FEATURES
ECONOMICAL OFF-LINE
FLYBACK OR FORWARD
CONVERTERS.
DC-DC BUCK OR BOOST
CONVERTERS.
LOW COST DC MOTOR
CONTROL.
7.5
7.8
-3s
8.3
Mean
8.8
+3s
9.3
Available Options
Start-Up
Max. Duty
Cycle
Part#
Hysteresis
Voltage
UCx842A
UCx843A
UCx844A
UCx845A
16V
8.4V
16V
6V
0.8V
6V
<100%
<100%
<50%
Discharge Current Distribution - mA
8.4A
0.8V
<50%
PACKAGE ORDER INFO
Plastic DIP
8-Pin
Plastic SOIC
8-Pin
Plastic SOIC
14-Pin
Ceramic DIP
8-Pin
M
DM
D
Y
TA (°C)
RoHS Compliant / Pb-free
Transition DC: 0503
RoHS Compliant / Pb-free Transition DC: 0440
0 to 70
-40 to +85
-55 to 125
UC384xAM
UC284xAM
-
UC384xADM
UC284xADm
-
UC384xAD
UC284xAD
-
-
UC284xAY
UC184xAY
Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. UC3842ADM-TR)
L
I N
F
I N I T Y
M
I C R O E L E C T R O N I C S
I N C .
Copyright © 1995
Rev. 1.2a,2005-03-09
1
11861 WESTERN
A
VENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: 714-893-2570