Datasheet

LOG112, 2112
5
SBOS246D
www.ti.com
TYPICAL CHARACTERISTICS
At T
A
= +25°C, V
S
= ±5V, and R
L
= 10kΩ, unless otherwise noted.
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
Normalized Output Voltage (V)
NORMALIZED TRANSFER FUNCTION
0.0001 0.001 0.01 0.1 1 10 100 1k
10k
Current Ratio, I
1
/I
2
V
LOGOUT
= (0.5V)LOG (I
1
/I
2
)
ONE CYCLE OF NORMALIZED TRANSFER FUNCTION
Normalized Output Voltage (V)
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
110
Current Ratio, I
1
/I
2
8
7
6
5
4
3
2
1
0
–1
–2
1nA 10nA 100nA 1µA10µA 100µA 1mA 10mA100pA
GAIN ERROR (I
2
= 1µA)
Input Current (I
1
or I
2
)
Gain Error (%)
–40°C
+75°C
–5°C +25°C
+85°C
–20
–15
–10
–5
0
5
10
15
20
–20
–15
–10
–5
0
5
10
15
20
1mA
10µA
100nA
1nA
10nA
100nA
1µA
10µA
100µA
1mA
1nA
I
1
I
2
Total Error (mV)
TOTAL ERROR (–5°C)
Total Error (mV)
10 to 15
5 to 10
0 to 5
–5 to 0
–20
–15
–10
–5
0
5
10
15
20
–20
–15
–10
–5
0
5
10
15
20
1mA
10µA
100µA
1µA
100nA
1nA
10nA
100nA
1µA
10µA
100µA
1mA
10nA
1nA
I
1
I
2
Total Error (mV) Total Error (mV)
5 to 10
0 to 5
–5 to 0
TOTAL ERROR (25°C)
–20
20
0
40
60
80
100
–20
0
20
40
60
80
100
1mA
10µA
100µA
1µA
100nA
1nA
10nA
100nA
1µA
10µA
100µA
1mA
10nA
1nA
I
1
I
2
Total Error (mV) Total Error (mV)
20 to 40
0 to 20
40 to 60
60 to 80
80 to 100
–20 to 0
TOTAL ERROR (70°C)