LT1011/LT1011A
Voltage Comparator
U
Response Time vs Overdrive
500
450
16
17
19
6012
12-BIT
D/A CONVERTER
INPUT
0V TO 10V
R4*
2.49k
R6
820Ω
PARALLEL
OUTPUTS
4
5V
24
E
12
START
CLOCK f = 1.4MHz
1011 TA01
FEATURES
s
s
s
s
s
s
s
s
s
DESCRIPTIO
Pin Compatible with LM111 Series Devices
Guaranteed
Max 0.5mV Input Offset Voltage
Guaranteed
Max 25nA Input Bias Current
Guaranteed
Max 3nA Input Offset Current
Guaranteed
Max 250ns Response Time
Guaranteed
Min 200,000 Voltage Gain
50mA Output Current Source or Sink
±30V
Differential Input Voltage
Fully Specified for Single 5V Operation
APPLICATIO S
s
s
s
s
s
s
s
SAR A/D Converters
Voltage-to-Frequency Converters
Precision RC Oscillator
Peak Detector
Motor Speed Control
Pulse Generator
Relay/Lamp Driver
, LTC and LT are registered trademarks of Linear Technology Corporation.
The LT
®
1011 is a general purpose comparator with sig-
nificantly better input characteristics than the LM111.
Although pin compatible with the LM111, it offers four
times lower bias current, six times lower offset voltage and
five times higher voltage gain. Offset voltage drift, a
previously unspecified parameter, is guaranteed at
15µV/°C. Additionally, the supply current is lower by a
factor of two with no loss in speed. The LT1011 is several
times faster than the LM111 when subjected to large
overdrive conditions. It is also fully specified for DC
parameters and response time when operating on a single
5V supply. These parametric improvements allow the
LT1011 to be used in high accuracy (≥12-bit) systems
without trimming. In a 12-bit A/D application, for instance,
using a 2mA DAC, the offset error introduced by the
LT1011 is less than 0.5LSB. The LT1011 retains all the
versatile features of the LM111, including single 3V to
±18V
supply operation, and a floating transistor output
with 50mA source/sink capability. It can drive loads refer-
enced to ground, negative supply or positive supply, and
is specified up to 50V between V
–
and the collector output.
A differential input voltage up to the full supply voltage is
allowed, even with
±18V
supplies, enabling the inputs to
be clamped to the supplies with simple diode clamps.
TYPICAL APPLICATIO
R1
1k
FULL-SCALE
TRIM
R2*
6.49k
15V
20
14
LM329
7V
R3
6.98k
15
10µs 12-Bit A/D Converter
3.9k
15V
*R2 AND R4
SHOULD TC TRACK
–15V
0.001µF
5V
R5
1k
RESPONSE TIME (ns)
13
12 11 10 9
PARALLEL
OUTPUTS
5
6
7
8
7
6
5
4
8
9
16 17 18 19 20 21
D
CP
CC
S
AM2504
SAR REGISTER
S
U
U
400
350
300
250
200
150
100
50
FALLING
OUTPUT
RISING
OUTPUT
18
3
2
1
2
+
LT1011A
7
3
–
SERIAL OUTPUT
7475
LATCH
0
0.1
1
10
OVERDRIVE (mV)
100
1011 TA02
1
LINER [ LINEAR TECHNOLOGY ]
