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LOG112, 2112
4
SBOS246D
www.ti.com
FREQUENCY RESPONSE, CORE LOG(5)
BW, 3dB
I2 = 10nA
CC = 4500pF
0.1
kH
I2 = 1ACC = 150pF
38
kH
I2 = 10ACC = 150pF
40
kH
I2 = 1mA
CC = 50pF
45
kHz
Step Response
Increasing
I1 = 10nA to 100nA
CC = 120pF, I2 = 31.6nA
1.1
ms
I1 = 1A to 100ACC = 375pF, I2 = 10A
1.6
s
I1 = 1A to 1mA
CC = 950pF, I2 = 31.6A
1.5
s
Decreasing
I1 = 100nA to 10nA
CC = 120pF, I2 = 31.6nA
2.1
ms
I1 = 100A to 1ACC = 375pF, I2 = 10A
31.2
s
I1 = 1mA to 1ACC = 950pF, I2 = 31.6A39
s
Increasing
I2 = 10nA to 100nA
CC = 125pF, I1 = 31.6nA
2.6
ms
I2 = 1A to 100ACC = 750pF, I1 = 10A
113
s
I2 = 1A to 1mA
CC = 10.5nF, I1 = 31.6A
1.2
ms
Decreasing
I2 = 100nA to 10nA
CC = 125pF, I1 = 31.6nA
630
s
I2 = 100A to 1ACC = 750pF, I1 = 10A
6.6
s
I2 = 1mA to 1ACC = 10.5nF, I1 = 31.6A
13.3
s
OP AMP, A3
Input Offset Voltage
+250
±1000
V
vs Temperature
TMIN to TMAX
±2
V/°C
vs Supply
VS
=
±4.5V to ±18V
5
50
V/V
Input Bias Current
–10
nA
Input Offset Current
±0.5
nA
Input Voltage Range
(V–)
(V+) – 1.5
V
Input Noise, f = 0.1Hz to 10Hz
1
V
PP
f = 1kHz
28
nV/√Hz
Open-Loop Voltage Gain
88
dB
Gain-Bandwidth Product
1.4
MHz
Slew Rate
0.5
V/
s
Settling Time, 0.01%
G = –1, 3V Step, CL = 100pF
16
s
Rated Output
(V–) + 1.5
(V+) – 0.9
V
Short-Circuit Current
±4mA
VOLTAGE REFERENCE
Bandgap Voltage
2.5
V
Error, Initial
±0.05
±0.5
%
vs Temperature
TMIN to TMAX
±25
ppm/
°C
vs Supply
VS = ±4.5V to ±18V
±10
ppm/V
vs Load
ILOAD = 10mA
±600
ppm/mA
Short-Circuit Current
16
mA
POWER SUPPLY
Operating Range
VS
±4.5
±18
V
Quiescent Current
IO = 0
LOG112
±1.25
±1.75
mA
LOG2112
±2.5
±3.5
mA
TEMPERATURE RANGE
Specified Range, TMIN to TMAX
–575
°C
Operating Range
–40
85
°C
Storage Range
–55
125
°C
Thermal Resistance,
θ
JA SO-14
110
°C/W
SO-16
80
°C/W
NOTES: (1) Log Conformity Error is the peak deviation from the best-fit-straight line of VO vs LOG(I1/I2) curve expressed as a percent of peak-to-peak full-scale
output. K, scale factor, equals 0.5V output per decade of input current. (2) Scale factor of core log function is trimmed to 0.5V output per decade change of input
current. (3) Worst-case Total Error for any ratio of I1/I2, as the largest of the two errors, when I1 and I2 are considered separately. (4) Total Error includes offset
voltage, bias current, gain, and log conformity. (5) Bandwidth (3dB) and transient response are a function of both the compensation capacitor and the level of input
current.
ELECTRICAL CHARACTERISTICS (Cont.)
Boldface limits apply over the specified temperature range, TA = –5°C to +75°C.
At TA = +25°C, VS = ±5V, and RL = 10k, unless otherwise noted.
LOG112, LOG2112
PARAMETER
CONDITION
MIN
TYP
MAX
UNITS