UC2840 ,PWM Controllerfeatures of these devices in-
clude a 1% accurate reference, provision for slow,
turn-on and duty ..
UC2840 ,PWM ControllerABSOLUTE MAXIMUM RATINGS
Symbol Parameter Test Conditions Unit
V, Supply Voltage + V. (pin 15)
V ..
UC2840N ,32V; 1000mW; programmable off-line PWM controllerfeatures required
by all types of switching power supply controllers,
the UC184O family has been ..
UC2841DW ,Programmable, Off-Line, PWM ControllerMAXIMUM RATINGS Supply Voltage, +V (Pin 15) (Note 2) Operating Junction Temperature . . . . . . . . ..
UC2841DW ,Programmable, Off-Line, PWM ControllerELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for TA = -55°C to + ..
UC2841DW ,Programmable, Off-Line, PWM ControllerELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for TA = -55°C to + ..
UM2301 , PIN DIODE
UM2301 , PIN DIODE
UM23C2001 , 131,072 X 8 BIT CMOS MASK - PROGRAMMABLE ROM
UM3481A , Multi-Melody Generator with Sleep Function
UM3561 , UM3561A Three Siren Sound Generator
UM3561A , CARACTERISTICAS
UC2840
PWM Controller
tice;))' (jii'i:'ikiiisrt)E -
i___M_l_@@@ElE@m©lll@$_
n ALL CONTROL, DRIVING, MONITORING, AND
PROTECTION FUNCTIONS INCLUDED
u LOW-CURRENT, OFF-LINE START CIRCUIT
n FEED-FORWARD LINE REGULATION OVER 4
TO 1 INPUT RANGE
n PWM LATCH FOR SINGLE PULSE PER PE-
n PULSE-BY-PULSE CURRENT LIMITING PLUS
SHUTDOWN FOR OVER-CURRENT FAULT
a NO START-UP OR SHUTDOWN TRANSIENTS
n SLOW TURN-ON AND MAXIMUM DUTY-CY-
CLE CLAMP
n SHUTDOWN UPON OVER-OR UNDERVOL-
TAGE SENSING
n LATCH OFF OR CONTINUOUS RETRY AFTER
:1 REMOTE, PULSE-COMMANDABLE START/
n PWM OUTPUT SWITCH USABLE TO 1A PEAK
CURRENT
I: 1% REFERENCE ACCURACY
n 500 kHz OPERATION
DESCRIPTION
Although containing most of the features required
by all types of switching power supply controllers,
the UC184O family has been optimized for highly-
efficient boot-strapped primaryside operation in for-
ward or flyback power converters. Two important
features for this mode are a starting circuit which re-
quires little current from the primary input voltage
and feed-forward control for constant Volt-second
operation over a wide input voltage range.
In addition to startup and normal regulating PWM
functions, these devices otter built-in protection from
over-voltage, under-voltage, and over-current fault
conditions. This monitoring circuitry contains the ad-
ded features that any fault will initiate a complete
shutdown with provisions for either latch off or auto-
matic restart. In the latch-off mode, the controller
may be started and stopped with external pulsed or
steady-state commands.
September 1988
H uditiiid
UC2840
UC3840
PROGRAMMABLE, OFF-LINE, PWM CONTROLLER
DIP-18
(Plastic and Ceramic)
Other performance features of these devices in-
clude a 1% accurate reference, provision for slow,
turn-on and duty-cycle limiting, and highspeed
pulse-by-pulse current limiting in addition to current
fault shutdown.
The UC1840's PWM output stage includes a latch
to insure only a single pulse per period and is des-
igned to optimize the turn off of an external switching
device by conducting during the "OFF" time with a
capability for both high peak current and low satu-
ration voltage. These devices are available in an 18-
pin dual-in-line plastic or ceramic package.
The UC184O is characterized for operation over the
full military temperature range of --5erC) to H250.
The UC2840 and UC3840 are designed for opera-
tion from -25 C to +85 C and 00 to +700, respec-
tively.
UC1840-UC2840-UC3840
PIN CONNECTION AND ORDER CODES
--NV-"
COMPENSATION d I IR l NON mvwnm
STMHI uv f I 11] (Nil WPUY
OVSENSE (o ‘6] bv nzr
STOP (e. ‘5] “" SUPPLY Type Plastic Ceramic
{ESET C, 1&1 OHWE n was UC1840 - UC1840J
UC2840 UC2840N UC2840J
$333315” (i, H] ammo UC3840 UC3840N U03840J
(LIvHZENV SLNSC v] PWM OUH'UT
'au'.jW HIM) 8 Il J v, SF NS)
”1lf" ( )0) RAM“
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Test Conditions Unit
V, Supply Voltage + V, (pin 15)
Voltage Driven 32 V
Current Driven 100 mA Maximum Self Limiting
V0 PWM Output Volage (pin 12) 40 V
l, PWM Output Current, Steady-state (pin 12) 400 mA
E0p PWM Output Peak Energy Discharge 20 pJ
Driver Bias Current (pin 14) -200 mA
I. REF; Reference Output Current (pin 16) - 50 mA
Slow Start Sink Current (pin 8) 20 mA
V) Sense Current (pin 11) 10 mA
Current Limit Inputs (pin 6, 7) - 0.5 to + 55 V
Comparator Inputs (pins 2, 3, 4, 5. 17, 18) - 0.3 to + 32 V
Ptot Power Dissipation at Tamb = 70 'C 1000 mW
T, Junction Temperature Range - 55 to + 150 "C
Top Operating Ambient Temperature Range : UC1840 - 55 to + 125 (
UC2840 - 25 to + 85 (
UC3840 0 to + 70 'C
Tstg Storage Temperature - 65 to + 150 'G
THERMAL DATA
Ru, )Vamb Thermal Resistance Junction-ambient Max 80 °C/W
F SGS-THOMSON
y, mmmmmmmms
