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UC3843AD

P1-P3P4-P6P7-P8
P
RODUCTION
D
ATA
S
HEET
T
HE
I
NFINITE
P
OWER OF
I
NNOVATION
L
IN
F
INITY
M
ICROELECTRONICS
I
NC
.
11861
W
ESTERN
A
VENUE
,
G
ARDEN
G
ROVE
,
CA.
92841,
714-898-8121,
F
AX
:
714-893-2570
1
Copyright © 1995
Rev. 1.2a,2005-03-09
UC184xA / 284xA / 384xA
C
URRENT
M
ODE
PWM
C
ONTROLLER
DESCRIPTION
The UC184xA family of control ICs provides
all the necessary features to implement off-line
fixed-frequency, current-mode switching power
supplies with a minimum of external
components. The current mode architecture
demonstrates improved load regulation, pulse-
by-pulse current limiting and inherent protection
of the power supply output switch. The IC
includes: A bandgap reference trimmed to ±1%
accuracy, an error amplifier, a current sense
comparator with internal clamp to 1V, a high
current totem pole output stage for fast
switching of power MOSFET's, and an
externally programmable oscillator to set
frequency and maximum duty cycle. The
undervoltage lock-out is designed to operate with
250µA typ. start-up current, allowing an efficient
bootstrap supply voltage design. Available
options for this family of products, such as start-
up voltage hysteresis and duty cycle, are
summarized below in the Available Options
section. The UC184xA family of control ICs is
also available in 14-pin SOIC package which
makes the Power Output Stage Collector and
Ground pins available.
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
PRODUCT HIGHLIGHT
C
OMPARISON
OF
UC384
X
A
VS
. SG384
X
D
ISCHARGE
C
URRENT
UC384xA
7.5 8.3 9.3
Mean
SG384x
Min. Limit
7.8
-3s
8.8
+3s
SG384x
Max. Limit
Discharge Current Distribution - mA
T
A
=25C
KEY FEATURES
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.
KEY FEATURES
ECONOMICAL OFF-LINE
FLYBACK OR FORWARD
CONVERTERS.
DC-DC BUCK OR BOOST
CONVERTERS.
LOW COST DC MOTOR
CONTROL.
Available Options
Part#
Start-Up
Voltage
Hysteresis
Max. Duty
Cycle
UCx842A 16V 6V <100%
UCx843A 8.4V 0.8V <100%
UCx844A 16V 6V <50%
UCx845A 8.4A 0.8V <50%
PACKAGE ORDER INFO
M
Plastic DIP
8-Pin
DM
Plastic SOIC
8-Pin
D
Plastic SOIC
14-Pin
Y
Ceramic DIP
8-Pin
T
A
(°C)
RoHS Compliant / Pb-free
Transition DC: 0503
RoHS Compliant / Pb-free Transition DC: 0440
0 to 70 UC384xAM UC384xADM UC384xAD -
-40 to +85 UC284xAM UC284xADm UC284xAD UC284xAY
-55 to 125 - - - UC184xAY
Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. UC3842ADM-TR)
C URRENT MODE PWM CONTROLLER
UC184xA/284xA/384xA
PRODUCT DATABOOK 1996/1997
Copyright © 1995
Rev. 1.2a 10/25
2
P
RODUCTION DATA SHEET
ABSOLUTE MAXIMUM RATINGS (Note 1)
Supply Voltage (Low Impedance Source) (V
CC
) ......................................................... 30V
Supply Voltage (I
CC
< 30mA).......................................................................... Self Limiting
Output Current ............................................................................................................. ±1A
Output Energy (Capacitive Load)................................................................................. 5µJ
Analog Inputs (V
FB
& I
SENSE
) ........................................................................ -0.3V to +6.3V
Error Amp Output Sink Current ............................................................................... 10mA
Power Dissipation at T
A
= 25°C (M Package) .............................................................. 1W
Storage Temperature Range .................................................................... -65°C to +150°C
Lead Temperature (Soldering, 10 Seconds) ............................................................. 300°C
PACKAGE PIN OUTS
Note 1. Exceeding these ratings could cause damage to the device. All voltages are with respect
to Ground. Currents are positive into, negative out of the specified terminal. Pin
numbers refer to DIL packages only.
1 8
27
36
45
M & Y PACKAGE
(Top View)
M PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θθ
θθ
θ
JA
95°C/W
DM PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θθ
θθ
θ
JA
165°C/W
D PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θθ
θθ
θ
JA
120°C/W
Y PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θθ
θθ
θ
JA
130°C/W
Junction Temperature Calculation: T
J
= T
A
+ (P
D
x θ
JA
).
The θ
JA
numbers are guidelines for the thermal performance of the device/pc-board system.
All of the above assume no ambient airflow
THERMAL DATA
DM PACKAGE
(Top View)
V
REF
V
CC
OUTPUT
GND
COMP
V
FB
I
SENSE
R
T
/C
T
1 8
27
36
45
V
REF
N.C.
V
CC
V
C
OUTPUT
GND
PWR GND
COMP
N.C.
V
FB
N.C.
I
SENSE
N.C.
R
T
/C
T
1 14
213
312
411
510
69
78
D PACKAGE
(Top View)
COMP
V
FB
I
SENSE
R
T
/C
T
V
REF
V
CC
OUTPUT
GND
Peak Package Solder Reflow Temp. (40 second max. exposure)..........................................260°C (+0, -5)
RoHS / Pb-free 100% Matte Tin Lead Finish
C URRENT MODE PWM CONTROLLER
UC184xA/284xA/384xA
PRODUCT DATABOOK 1996/1997
3
Copyright © 1995
Rev. 1.2a 10/25
P RODUCTION DATA SHEET
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply over the operating ambient temperatures for UC384xA with 0°C ≤ T
A
≤ 70°C, UC284xA with -40°C ≤ T
A
≤ 85°C,
UC184xA with -55°C ≤ T
A
≤ 125°C; V
CC
=15V; R
T
=10K; C
T
=3.3nF. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal
to the ambient temperature.)
Reference Section
Parameter
Symbol
Test Conditions
Output Voltage V
REF
T
J
= 25°C, I
L
= 1mA
Line Regulation 12 ≤ V
IN
≤ 25V
Load Regulation 1 ≤ I
O
≤ 20mA
Temperature Stability (Note 2 & 7)
Total Output Variation Over Line, Load, and Temperature
Output Noise Voltage (Note 2) V
N
10Hz ≤ f ≤ 10kHz, T
J
= 25°C
Long Term Stability (Note 2) T
A
= 125°C, t = 1000hrs
Output Short Circuit Current I
SC
UC384xA
Units
Min. Typ. Max. Min. Typ. Max.
UC184xA/284xA
4.95 5.00 5.05 4.90 5.00 5.10 V
620 620 mV
625 625 mV
0.2 0.4 0.2 0.4 mV/°C
4.9 5.1 4.82 5.18 V
50 50 µV
525 525 mV
-30 -100 -180 -30 -100 -180 mA
Oscillator Section
Initial Accuracy (Note 6) T
J
= 25°C
Voltage Stability 12 ≤ V
CC
≤ 25V
Temperature Stability (Note 2) T
MIN
≤ T
A
≤ T
MAX
Amplitude (Note 2)
Discharge Current T
J
= 25°C, V
PIN 4
= 2V
V
PIN 4
= 2V, T
MIN
≤ T
A
≤ T
MAX
47 52 57 47 52 57 kHz
0.2 1 0.2 1 %
55%
1.7 1.7 V
7.8 8.3 8.8 7.8 8.3 8.8 mA
7.5 8.8 7.6 8.8 mA
Output Low Level
V
OL
I
SINK
= 20mA
I
SINK
= 200mA
Output High Level
V
OH
I
SOURCE
= 20mA
I
SOURCE
= 200mA
Rise Time (Note 2) T
R
T
J
= 25°C, C
L
= 1nF
Fall Time (Note 2) T
F
T
J
= 25°C, C
L
= 1nF
UVLO Saturation V
SAT
V
CC
= 5V, I
SINK
= 10mA
Current Sense Section
Gain (Note 3 & 4) A
VOL
Maximum Input Signal (Note 3) V
PIN 1
= 5V
Power Supply Rejection Ratio (Note 3) PSRR 12 ≤ V
CC
≤ 25V
Input Bias Current I
B
Delay to Output (Note 2) T
pd
V
PIN 3
= 0 to 2V
Output Section
2.85 3 3.15 2.85 3 3.15 V/V
0.9 1 1.1 0.9 1 1.1 V
70 70 dB
-2 -10 -2 -10 µA
150 300 150 300 ns
0.1 0.4 0.1 0.4 V
1.5 2.2 1.5 2.2 V
13 13.5 13 13.5 V
12 13.5 12 13.5 V
50 150 50 150 ns
50 150 50 150 ns
0.7 1.2 0.7 1.2 V
(Electrical Characteristics continue next page.)
Error Amp Section
Input Voltage V
PIN 1
= 2.5V
Input Bias Current I
B
Open Loop Gain A
VOL
2 ≤ V
O
≤ 4V
Unity Gain Bandwidth (Note 2) UGBW T
j
= 25°C
Power Supply Rejection Ratio (Note 3) PSRR 12 ≤ V
CC
≤ 25V
Output Sink Current I
OL
V
PIN 2
= 2.7V, V
PIN 1
= 1.1V
Output Source Current I
OH
V
PIN 2
= 2.3V, V
PIN 1
= 5V
Output Voltage High Level V
OH
V
PIN 2
= 2.3V, R
L
= 15K to ground
Output Voltage Low Level V
OL
V
PIN 2
= 2.7V, R
L
= 15K to V
REF
2.45 2.50 2.55 2.42 2.50 2.58 V
-0.3 -1 -0.3 -2 µA
65 90 65 90 dB
0.7 1 0.7 1 MHz
60 70 60 70 dB
26 26 mA
-0.5 -0.8 -0.5 -0.8 mA
56 56 V
0.7 1.1 0.7 1.1 V
P1-P3P4-P6P7-P8

UC3843AD

Mfr. #:
Buy UC3843AD
Manufacturer:
Texas Instruments
Description:
Switching Controllers Current Mode
Lifecycle:
New from this manufacturer.
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