LTC1261IS8 Linear Technology, LTC1261IS8 Datasheet - Page 14

• Manufacturer Part Number: LTC1261IS8
• Description: IC VOLT INVERT SW CAP ADJ 8SOIC
• Manufacturer: Linear Technology
• Type: Switched Capacitor (Charge Pump), Invertingr

Specifications of LTC1261IS8

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: -1.25 ~ -8 V
• Current - Output: 15mA
• Frequency - Switching: 550kHz
• Voltage - Input: 3 ~ 8 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -

This circuit uses the LTC1261CS8 to generate a – 1.24V
output at 20mA. Attached to this output is a 312 resistor
to make the current/voltage conversion. 4mA through
312
through 312 gives 6.24V across the resistor, giving a net
5V output. If the 4mA to 20mA source requires an operat-
ing voltage greater than 8V, it should be powered from a
LTC1261
TYPICAL APPLICATIONS
14
generates 1.24V, giving a net 0V output. 20mA
TO 20mA
SENSOR
– 1.24V Generator for 4mA-20mA to 0V-5V Conversion
4mA
U
+
–
N
PROTECTION
OPTIONAL
DIODES
INPUT
–1.24V
1N5817
separate supply; the LTC1261 can then be powered from
any convenient supply, 3V V
prevents the external voltage from damaging the LTC1261
in shutdown or under fault conditions. The LTC1261’s
reference is trimmed to 3.5% and the resistor adds 1%
uncertainty, giving 4.5% total output error.
+
312
1%
3.3 F
6
5
OUT
ADJ
LTC1261
GND
V
8V
CC
1
4
C1
C1
+
–
2
3
0V TO 5V
LTC1261 • TA11
5%
1 F
0.1 F
S
8V. The Schottky diode