Philips Semiconductors Linear Products
Product specification
Sample-and-hold amplifier
NE/SE5537
DESCRIPTION
PIN CONFIGURATIONS
The NE5537 monolithic sample-and-hold amplifier combines the
best features of ion-implanted JFETs with bipolar devices to obtain
high accuracy, fast acquisition time, and low droop rate. This device
is pin-compatible with the LF198, and features superior performance
in droop rate and output drive capability. The circuit shown in Figure
1 contains two operational amplifiers which function as a unity gain
amplifier in the sample mode. The first amplifier has bipolar input
transistors which give the system a low offset voltage. The second
amplifier has JFET input transistors to achieve low leakage current
from the hold capacitor. A unique circuit design for leakage current
cancellation using current mirrors gives the NE5537 a low droop
rate at higher temperature. The output stage has the capability to
drive a 2kΩ load. The logic input is compatible with TTL, PMOS or
CMOS logic. The differential logic threshold is 1.4V with the sample
mode occurring when the logic input is high. It is available in 8-lead
TO-5, 8-pin plastic DIP packages, and 14-pin SO packages.
FE and N Packages
1
2
3
4
8
7
6
5
V+
LOGIC
OFFSET ADJUST
LOGIC REFERENCE
C
h
INPUT
V–
OUTPUT
1
D Package
1
14
13
12
11
10
9
V
ADJ
INPUT
OS
2
3
4
5
6
7
NC
V+
NC
V–
NC
LOGIC
LOGIC REFERENCE
NC
NC
NC
FEATURES
• Operates from ±5V to ±18V supplies
8
C
h
OUTPUT
NOTE:
• Hold leakage current 6pA @ T = 25°C
J
1. SO and non-standard pinouts.
• Less than 4µs acquisition time
• TTL, PMOS, CMOS compatible logic input
• 0.5mV typical hold step at CH=0.01µF
• Low input offset: 1MV (typical)
BLOCK DIAGRAM
OFFSET
2
• 0.002% gain accuracy with R =2kΩ
L
30k
• Low output noise in hold mode
5
• Input characteristics do not change during hold mode
• High supply rejection ratio in sample or hold
• Wide bandwidth
–
OUTPUT
3
+
INPUT
8
LOGIC
300
–
7
+
LOGIC
REFERENCE
6
HOLD
CAPACITOR
ORDERING INFORMATION
DESCRIPTION
TEMPERATURE RANGE
0 to +70°C
ORDER CODE
NE5537N
DWG #
8-Pin Plastic Dual In-Line Package (DIP)
14-Pin Plastic Small Outline (SO) Package
8-Pin Plastic Dual In-Line Package (DIP)
0404B
0175D
0404B
0 to +70°C
NE5537D
-55°C to +125°C
SE5537FE
884
August 31, 1994
853-1044 13721