ISO255 is isolation amplifier by Burr-Brown with some unique features enlisted below.
- ISO255 have dedicated power port isolated from both input and output sides
- ISO255 have built-in isolated DC-DC converter for input circuit and output circuit
- ISO255 have syc feature to synchronize modulation frequencies of all ISO255 IC’s in circuit.
- Gain can be adjusted by applying an external resistor between +Rg and -Rg pins.
- input/output Signal Common pins are separate from power GND pins. May be combined externally.
- Input is double line +Vin and -Vin.
Here is ISO255 example circuit which feeding a resistance bridge circuit output voltage for further measurement with being isolated from next circuitry.
+15V are applied on +Vs3 and GND3 pins. +Vs1,-Vs1 and +Vs2, -Vs2 are outputs of internal DC/DC converter. And filtered by 220nF capacitors. Output offset is adjusted by 200kΩ trimmer. In this example gain is unity due to +Rg and -Rg pins are open. Gain can be controlled by connecting +Rg and -Rg pins to a resistor. Gain may be calculated by following formula.
G = 1 + 50KΩ / Rg
ISO255 important parameters
- Input voltage range is ±10V
- Output voltage range is ±10V
- Small signal bandwidth is up to 50KHz
- Gain Error 0.15% at G=1
- Input offset maximum ± (0.125 + 101/G)
- Power supply voltage range : 11V~18V
- Sync frequency range: 1MHz ~ 1.4MHz
- Isolation leakage current: 2uA maximum @ 240V 50Hz
- Isolation Mode Voltage IMV ,dV/dt: 20kV/uS
- Isolation barrier impedance: 1014 Ω || 2pF
- Isolation Voltage: 2500V
- Available packages: 28 pin plastic DIP 0.6″ wide
- Operating temperature range: -40°C ~ 85°C
Isolation Mode voltage is voltage between GND1 and GND2.
Other relevant IC
AD215 isolation amplifier AMC1200/B ISO124U SI8920 ISO120 AD202 PS8551AL4-AX ADUM4190 ADUM3190 AD204 AMC1301 NJM41005-T AD215 AMC1300 AMC1302 AMC1200/B ISO224 AMC1211A-Q1 AMC1301DWVR MAX14850 ADuM6132 ADuM3150 HCPL-7800 ISO124, ISO122