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LIN D O C #: 1840 |
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UC184xA/284xA/384xA |
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C U R R E N T M O D E P W M C O N T R O L L E R |
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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 |
P R O D U C T I O N D A T A S H E E T |
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D E S C R I P T I O N
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.
P R O D U C T H I G H L I G H T
COMPARISON OF UC384XA VS. SG384X DISCHARGE CURRENT
K E Y F E AT U R E S
■LOW START-UP CURRENT. (0.5mA max.)
■TRIMMED OSCILLATOR DISCHARGE CURRENT. (See Product Highlight)
pOPTIMIZED FOR OFF-LINE AND DC-TO-DC CONVERTERS.
pAUTOMATIC FEED FORWARD COMPENSATION.
pPULSE-BY-PULSE CURRENT LIMITING.
pENHANCED LOAD RESPONSE CHARACTERISTICS.
pUNDER-VOLTAGE LOCKOUT WITH HYSTERESIS.
pDOUBLE PULSE SUPPRESSION.
pHIGH-CURRENT TOTEM POLE OUTPUT.
pINTERNALLY TRIMMED BANDGAP REFERENCE.
p500KHz OPERATION.
pLOW RO ERROR AMPLIFIER.
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UC384xA |
SG384x |
SG384x |
Min. Limit |
Max. Limit |
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TA=25°C |
7.5 |
7.8 |
8.3 |
8.8 |
9.3 |
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−3σ |
Mean |
+3σ |
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Discharge Current Distribution - mA
A P P L I C AT I O N S
■ECONOMICAL OFF-LINE FLYBACK OR FORWARD CONVERTERS.
■DC-DC BUCK OR BOOST CONVERTERS.
■LOW COST DC MOTOR CONTROL.
A V A I L A B L E |
O P T I O N S |
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Part # |
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Start-Up |
Hysteresis |
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Max. Duty |
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Voltage |
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Cycle |
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UCx842A |
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16V |
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6V |
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<100% |
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UCx843A |
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8.4V |
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0.8V |
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<100% |
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UCx844A |
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16V |
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6V |
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<50% |
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UCx845A |
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8.4V |
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0.8V |
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<50% |
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PA C K A G E O R D E R I N F O R M AT I O N
TA (°C) |
M |
Plastic DIP |
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DM |
Plastic SOIC |
D |
Plastic SOIC |
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Y |
Ceramic DIP |
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8-pin |
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8-pin |
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14-pin |
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8-pin |
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0 to 70 |
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UC384xAM |
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UC384xADM |
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UC384xAD |
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-40 to 85 |
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UC284xAM |
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UC284xADM |
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UC284xAD |
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UC284xAY |
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-55 to 125 |
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— |
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— |
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— |
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UC184xAY |
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Note: All surface-mount packages are available in Tape & Reel. Append the letter "T" to part number. (i.e. UC3842ADMT)
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F O R F U R T H E R I N F O R M AT I O N C A L L ( 7 1 4 ) 8 9 8 - 8 1 2 1 |
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Copyright © 1995 |
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11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841 |
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Rev. 1.2 12/95 |
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
UC184xA/284xA/384xA
C U R R E N T M O D E P W M C O N T R O L L E R
P R O D U C T I O N D A T A S H E E T
ABSOLUTE MAXIMUM RATINGS |
(Note 1) |
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Supply Voltage (Low Impedance Source) (VCC) ......................................................... |
30V |
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Supply Voltage (ICC < 30mA).......................................................................... |
Self Limiting |
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Output Current ............................................................................................................. |
±1A |
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Output Energy (Capacitive Load)................................................................................. |
5µJ |
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Analog Inputs (VFB & ISENSE) ........................................................................ |
-0.3V to +6.3V |
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Error Amp Output Sink Current ............................................................................... |
10mA |
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Power Dissipation at TA = 25°C (M Package) .............................................................. |
1W |
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Storage Temperature Range .................................................................... |
-65°C to +150°C |
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Lead Temperature (Soldering, 10 Seconds) ............................................................. |
300°C |
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.
THERMAL DATA
M PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA |
95°C/W |
DM PACKAGE: |
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THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA |
165°C/W |
D PACKAGE: |
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THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA |
120°C/W |
Y PACKAGE: |
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THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA |
130°C/W |
Junction Temperature Calculation: TJ = TA + (PD x θJA).
The θJA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow
PACKAGE PIN OUTS
COMP |
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1 |
8 |
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VREF |
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VFB |
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2 |
7 |
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VCC |
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ISENSE |
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3 |
6 |
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OUTPUT |
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RT/CT |
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4 |
5 |
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GND |
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M & Y PACKAGE
(Top View)
COMP |
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1 |
8 |
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VREF |
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VFB |
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2 |
7 |
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VCC |
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ISENSE |
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3 |
6 |
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OUTPUT |
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RT/CT |
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4 |
5 |
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GND |
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DM PACKAGE
(Top View)
COMP |
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1 |
14 |
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VREF |
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N.C. |
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2 |
13 |
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N.C. |
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VFB |
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3 |
12 |
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VCC |
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N.C. |
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4 |
11 |
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VC |
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ISENSE |
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5 |
10 |
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OUTPUT |
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N.C. |
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6 |
9 |
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GND |
RT/CT |
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7 |
8 |
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PWR GND |
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D PACKAGE
(Top View)
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Copyright © 1995 |
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Rev. 1.2 12/95 |
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P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
UC184xA/284xA/384xA
C U R R E N T M O D E P W M C O N T R O L L E R
P R O D U C T I O N D A T A S H E E T
E L E C T R I C A L C H A R A C T E R I S T I C S
(Unless otherwise specified, these specifications apply over the operating ambient temperatures for UC384xA with 0°C ≤ TA ≤ 70°C, UC284xA with -40°C ≤ TA ≤ 85°C, UC184xA with -55°C ≤ TA ≤ 125°C; VCC=15V; RT=10K; CT=3.3nF. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to the ambient temperature.)
Parameter |
Symbol |
Test Conditions |
UC184xA/284xA |
UC384xA |
Units |
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Min. Typ. Max. Min. Typ. Max. |
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Reference Section |
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Output Voltage |
VREF |
TJ = 25°C, IL = 1mA |
4.95 |
5.00 |
5.05 |
4.90 |
5.00 |
5.10 |
V |
Line Regulation |
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12 ≤ VIN ≤ 25V |
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6 |
20 |
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6 |
20 |
mV |
Load Regulation |
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1 ≤ IO ≤ 20mA |
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6 |
25 |
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6 |
25 |
mV |
Temperature Stability (Note 2 & 7) |
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0.2 |
0.4 |
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0.2 |
0.4 |
mV/°C |
Total Output Variation |
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Over Line, Load, and Temperature |
4.9 |
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5.1 |
4.82 |
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5.18 |
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Output Noise Voltage (Note 2) |
VN |
10Hz ≤ f ≤ 10kHz, TJ = 25°C |
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50 |
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50 |
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µV |
Long Term Stability (Note 2) |
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TA = 125°C, t = 1000hrs |
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5 |
25 |
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5 |
25 |
mV |
Output Short Circuit Current |
ISC |
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-30 |
-100 |
-180 |
-30 |
-100 |
-180 |
mA |
Oscillator Section |
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Initial Accuracy (Note 6) |
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TJ = 25°C |
47 |
52 |
57 |
47 |
52 |
57 |
kHz |
Voltage Stability |
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12 ≤ VCC ≤ 25V |
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0.2 |
1 |
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0.2 |
1 |
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Temperature Stability (Note 2) |
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TMIN ≤ TA ≤ TMAX |
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5 |
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5 |
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% |
Amplitude (Note 2) |
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1.7 |
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1.7 |
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V |
Discharge Current |
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TJ = 25°C, VPIN 4 = 2V |
7.8 |
8.3 |
8.8 |
7.8 |
8.3 |
8.8 |
mA |
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VPIN 4 = 2V, TMIN ≤ TA ≤ TMAX |
7.5 |
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8.8 |
7.6 |
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8.8 |
mA |
Error Amp Section |
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Input Voltage |
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VPIN 1 = 2.5V |
2.45 |
2.50 |
2.55 |
2.42 |
2.50 |
2.58 |
V |
Input Bias Current |
IB |
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-0.3 |
-1 |
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-0.3 |
-2 |
µA |
Open Loop Gain |
AVOL |
2 ≤ VO ≤ 4V |
65 |
90 |
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65 |
90 |
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dB |
Unity Gain Bandwidth (Note 2) |
UGBW |
Tj = 25°C |
0.7 |
1 |
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0.7 |
1 |
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MHz |
Power Supply Rejection Ratio (Note 3) |
PSRR |
12 ≤ VCC ≤ 25V |
60 |
70 |
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60 |
70 |
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dB |
Output Sink Current |
IOL |
VPIN 2 = 2.7V, VPIN 1 = 1.1V |
2 |
6 |
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2 |
6 |
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mA |
Output Source Current |
IOH |
VPIN 2 = 2.3V, VPIN 1 = 5V |
-0.5 |
-0.8 |
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-0.5 |
-0.8 |
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mA |
Output Voltage High Level |
VOH |
VPIN 2 = 2.3V, RL = 15K to ground |
5 |
6 |
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5 |
6 |
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V |
Output Voltage Low Level |
VOL |
VPIN 2 = 2.7V, RL = 15K to VREF |
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0.7 |
1.1 |
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0.7 |
1.1 |
V |
Current Sense Section |
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Gain (Note 3 & 4) |
AVOL |
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2.85 |
3 |
3.15 |
2.85 |
3 |
3.15 |
V/V |
Maximum Input Signal (Note 3) |
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VPIN 1 = 5V |
0.9 |
1 |
1.1 |
0.9 |
1 |
1.1 |
V |
Power Supply Rejection Ratio (Note 3) |
PSRR |
12 ≤ VCC ≤ 25V |
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70 |
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70 |
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dB |
Input Bias Current |
IB |
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-2 |
-10 |
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-2 |
-10 |
µA |
Delay to Output (Note 2) |
Tpd |
VPIN 3 = 0 to 2V |
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150 |
300 |
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150 |
300 |
ns |
Output Section |
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Output Low Level |
VOL |
ISINK = 20mA |
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0.1 |
0.4 |
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0.1 |
0.4 |
V |
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ISINK = 200mA |
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1.5 |
2.2 |
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1.5 |
2.2 |
V |
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Output High Level |
VOH |
ISOURCE = 20mA |
13 |
13.5 |
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13 |
13.5 |
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V |
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ISOURCE = 200mA |
12 |
13.5 |
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12 |
13.5 |
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V |
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Rise Time (Note 2) |
TR |
TJ = 25°C, CL = 1nF |
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50 |
150 |
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50 |
150 |
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Fall Time (Note 2) |
TF |
TJ = 25°C, CL = 1nF |
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50 |
150 |
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50 |
150 |
ns |
UVLO Saturation |
VSAT |
VCC = 5V, ISINK = 10mA |
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0.7 |
1.2 |
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0.7 |
1.2 |
V |
(Electrical Characteristics continue next page.)
Copyright © 1995 |
3 |
Rev. 1.2 12/95 |