Texas Instruments UC3904N, UC3904DWTR, UC3904DW, UC2904J, UC2904DW Datasheet
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BLOCK DIAGRAM
Note: Pin Numbers refer to J, N, and DW Packages.
4/97
The UC1904 Quad Supp ly Moni tor will respo nd to un der- and over-voltage conditi o ns on u p to four c on ti nu ou s ly m on itor ed voltage levels. Four
independen t positive voltages can be monitor ed or, alternatively, two of
the sense in puts are preset t o monitor -5V and -12V supplies. The device also monitors Over-Current and Line Sense inputs, both with precision input thresholds.
Four open collector outputs on the UC1904 give the following responses: 1. The
OV/OC output is a l a tc h ed over-voltag e, or over-current
response. 2. A Power Good signal responds low with any fault detection
– on power-up a pro grammable delay is use d to hol d this output low for
a system Power On Reset signal. 3. The
PWRW output responds only to
a Line Sense inp ut, for ea rl y warning of power failu res. 4. The last open
collector, the ON/
OFF output, gener ates a delayed supply OFF control
signal in re sponse to an OFF input comma nd, under-voltage condition,
or line fault detection.
The OV-UV fault window is adjustable with a programming input. The
thresholds are centered around the precision 2.5V reference, with a
scaled hystere sis for precise, glitch free operation. In the positive mode
of operation, the fault windows at each of the sens e inputs can be independently s c a l ed u sing external resis tors and the 2.5V r eference output.
An Auto Restar t functio n couples with the under-voltage and line sensing circuits to allow controlled power supply start-up and shutdown.
This device will operate over a supply range of 4.75V to 18V. The device
is available in a DIP, SOIC, or PLCC outline. This device is ESD protected on all pins.
• Inputs for Monitoring Up to Four
Supply Voltages
• Two Inputs Preset for -5V and -12V
Monitoring, or Programmable
Positive Levels
• Precision 2.5V Reference
• Separate Inputs for Over-Current and
Line Fault Sensing
• Adjustable Under- to Over-Voltage
Fault Windows
• Latched Over-Voltage and
Over-Current Output
• Power Good and Power Warning
Outputs
• Auto Restart Function with ON/OFF
Control, and Programmable Delay
• Programmable Pwr On Reset Delay
UC1904
UC2904
UC3904
Precision Quad Supply and Line Monitor
FEATURES
DESCRIPTION
UC1904
UC2904
UC3904
Input Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V
Sense Inputs, S1 And S2, Other Analog And Logic Inputs
Maximum Forced Voltage . . . . . . . . . . . . . . . . . . -0.3V to 10V
Maximum Forced Current . . . . . . . . . . . . . . . . . . . . . . ±10mA
Sense Input S3, (-12V Sense Input)
Maximum Forced Voltage . . . . . . . . . . . . . . . . . . -18V to 10V
Maximum Forced Current . . . . . . . . . . . . . . . . . . . . . . ±10mA
Sense Input S4, (-5V Sense Input)
Maximum Forced Voltage . . . . . . . . . . . . . . . . . . -10V to 10V
Maximum Forced Current . . . . . . . . . . . . . . . . . . . . . . ±10mA
Open Collector Outputs
Maximum Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V
Maximum Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA
Reference Output Current . . . . . . . . . . . . . . . Internally Limited
Operating Junction Temperature . . . . . . . . . . . -55°C to +150°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . -65°C to +150°C
PACKAGE PIN FUNCTION
FUNCTION PIN
2.5V 1
POR DLY 2
N.C. 3
S1 4
S2 5
S3 6
S4 7
N.C. 8
LS Input 9
OC Input 10
PWRW Out 11
PG Out 12
OV/OC Out 13
V
IN
14
ON/
OFF Out 15
OFF DLY
16
ON/OFF Input 17
ARST Input 18
W
ADJ
19
Gnd 20
DIL-18, SOIC-18 (TOP VIEW)
J or N PACKAGE, DW PACKAGE
PLCC-20 (TOP VIEW)
Q PACKAGE
CONNECTION DIAGRAMS
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Note 1: Unless otherwise indicated, voltages are reference to
ground and currents are positive into, negative out of, the specified terminals.
Unless otherwise stated, these specifications hold for TA = 0 to 70°C for the
UC3904, -40 to +85°C for the UC2904, and -55 to +1 25°C for the UC1904, +VIN =
15V, W
ADJ
= 0.5V, Sense Inputs 1-4, OC and LS Inputs = 2.5V. The ON/OF F In pu t
and the ARST Input = 0V.
ELECTRICAL CHARACTERISTICS:
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Input Supply
V
IN
Supply Current VIN = 15V 3.2 4.5 mA
V
IN
UVLO Threshold Low to High 4.5 4.75 V
UVLO Threshold Hysteresis 50 mV
Minimum VIN to Enable PG Out 0.8 1.5 V
Reference
Output Voltage(V
REF
)T
J
= 25°C 2.475 2.5 2.525 V
Over Temperature, UC3904 2.47 2.53 V
Over Temperature, UC2904 & UC1904 2.465 2.535 V
Load Regulation I
OUT
= 0 to 4mA 6 mV
Line Regulation V
IN
= 4.75 to 18V 5 mV
Short Circuit Current V
REF
= 0V 17 mA
OV UV Window, LS Input, OC Input, ARST Input, and
ON/OFF Input Thresholds
Over-Voltage Thresholds W
ADJ
= 0.25V, Offset from V
REF
, Input L to H 110 125 140 mV
S1, S2 W
ADJ
= 0.5V, Offset from V
REF
, Input L to H 230 250 270 mV
W
ADJ
= 1V, Offset from V
REF
, Input L to H 460 500 540 mV
Over-Voltage Thresholds W
ADJ
= 0.25V, Offset from V
REF
, Input L to H 110 125 145 mV
S3, S4 Positive Mode W
ADJ
= 0.5V, Offset from V
REF
, Input L to H 230 250 280 mV
W
ADJ
= 1V, Offset from V
REF
, Input L to H 460 500 550 mV
2
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