CURRENT CONVERTER IC

AM402

analog microelectronics

April 99

3/8

Parameter

Symbol

Conditions

Min.

Typ.

Max.

Unit

V/I Converter

Internal Gain

GVI

1.00

Trim Range

adjustable by R0

0.75

1.00

1.25

Voltage Range at R0 FS

VR0FS

400

500

580

mV

Offset Voltage

VOS

βF ≥ 100

±

2

±

6mV

VOS vs. Temperature

dVOS/dT

βF ≥ 100

±

7

±

20

µV/°C

Output Offset Current

IOUTOS

3–wire operation

–35

–50

µA

IOUTOS vs. Temperature

dIOUTOS/dT

3–wire operation

55

80

nA/°C

Output Offset Current

IOUTOS

2–wire operation

14

22

µA

IOUTOS vs. Temperature

dIOUTOS/dT

2–wire operation

22

35

nA/°C

Output Control Current

IOUTC

2–wire operation, VR0/100mV

5

µA

IOUTC vs. Temperature

dIOUTC/dT

2–wire operation

–9

nA/°C

Output Voltage Range

VOUT

VOUT = RL IOUT, VCC < 16V

0

VCC – 6

V

VOUT

VOUT = RL IOUT, VCC

≥ 16V

010

V

Output Current Range FS

IOUTFS

IOUT = VR0/R0, 3–wire operation

20

mA

Output Resistance

ROUT

0.5

1.0

M

Ω

Load Capacitance

CL

0

500

nF

Protection Functions

Voltage Limitation at R0

VLIMR0

VR0 = VIN GIA, SET = GND

580

640

700

mV

VLIMR0

VIN = 0, VR0 = VSET/2

580

635

690

mV

Temperature Limitation

TLIMIT

110

130

150

°C

Protection against reverse polarity

Ground vs. VS vs. IOUT

35

V

Current in case of reverse polarity

Ground = 35V, VS = IOUT = 0

3.8

mA

System Parameters

Nonlinearity

ideal input

0.05

0.15

%FS

* In 2–wire operation a maximum current of IOUTmin – ICC is valid

Currents flowing into the IC are negative

BOUNDARY CONDITIONS

Parameter

Symbol

Conditions

Min.

Typ.

Max.

Unit

Sense Resistor

R0

IOUTFS = 20mA

202529

Ω

R0

c = 20mA/IOUTFS

c

⋅ 20

c

⋅ 25

c

⋅ 29

Ω

Stabilisation Resistor

R5

IOUTFS = 20mA

354045

Ω

R5

c = 20mA/IOUTFS

c

⋅ 35

c

⋅ 40

c

⋅ 45

Ω

Load Resistance

RL

limitation only for 3–wire operation

0

500

Ω

Sum Gain Resistors

R1 + R2

25

50

k

Ω

Sum Offset Resistors

R3 + R4

20

200

k

Ω

VREF Capacitance

C1

1.9

2.2

5.0

µF

Output Capacitance

C2

only for 2–wire operation

90

100

250

nF

D1 Breakdown Voltage

VBR

35

50

V

T1 Forward Current Gain

βF

50

150