
Precision Micropower, Low Dropout
Voltage References
REF19x Series
FEATURES 
Initial accuracy: ±2 mV maximum 
Temperature coefficient: 5 ppm/°C maximum 
Low supply current: 45 μA maximum 
Sleep mode: 15 μA maximum 
Low dropout voltage 
Load regulation: 4 ppm/mA 
Line regulation: 4 ppm/V 
High output current: 30 mA 
Short-circuit protection 
Rev. I 
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APPLICATIONS 
Portable instruments 
ADCs and DACs 
Smart sensors 
Solar-powered applications 
Loop current-powered instruments 
GENERAL DESCRIPTION 
The REF19x series precision band gap voltage references use a 
patented temperature drift curvature correction circuit and 
laser trimming of highly stable, thin-film resistors to achieve a 
very low temperature coefficient and high initial accuracy. 
The REF19x series is made up of micropower, low dropout 
voltage (LDV) devices, providing stable output voltage from 
supplies as low as 100 mV above the output voltage and 
consuming less than 45 μA of supply current. In sleep mode, 
which is enabled by applying a low TTL or CMOS level to the 
SLEEP pin, the output is turned off, and supply current is 
further reduced to less than 15 μA. 
The REF19x series references are specified over the extended 
industrial temperature range (40°C to +85°C), with typical 
performance specifications over 40°C to +125°C for 
applications such as automotive. 
All electrical grades are available in an 8-lead SOIC_N package; 
the PDIP and TSSOP packages are available only in the lowest 
electrical grade. Products are also available in die form. 
TEST PINS 
Test Pin 1 and Test Pin 5 are reserved for in-package Zener zap. 
To achieve the highest level of accuracy at the output, the Zener 
zapping technique is used to trim the output voltage. Since each 
unit may require a different amount of adjustment, the resistance 
value at the test pins varies widely from pin to pin and from 
part to part. The user should leave Pin 1 and Pin 5 
unconnected. 
REF19x
SERIES
TOP VIEW
(Not to Scale)
TP
1
V
S
2
SLEEP
3
GND
4
NC
NC
OUTPUT
TP
8
7
6
5
NOTES
1. NC = NO CONNECT.
2. TP PINS ARE FACTORY TEST
    POINTS, NO USER CONNECTION.
Figure 1. 8-Lead SOIC_N and TSSOP Pin Configuration 
(S Suffix and RU Suffix) 
0
REF19x
SERIES
TOP VIEW
(Not to Scale)
TP
1
V
S
2
SLEEP
3
GND
4
NC
NC
OUTPUT
TP
8
7
6
5
NOTES
1. NC = NO CONNECT.
2. TP PINS ARE FACTORY TEST
    POINTS, NO USER CONNECTION.
0
Figure 2. 8-Lead PDIP Pin Configuration  
(P Suffix) 
Table 1. Nominal Output Voltage 
Part Number 
REF191 
REF192 
REF193 
REF194 
REF195 
REF196 
REF198 
Nominal Output Voltage (V) 
2.048 
2.50 
3.00 
4.50 
5.00 
3.30 
4.096