1988 Burr-Brown Corporation
PDS-851D
Printed in U.S.A. October, 1993
FEATURES
q
COMPLETELY FLOATING:
No Power Supply or Ground Connections
q
HIGH ACCURACY: 100
A
0.5%
q
LOW TEMPERATURE COEFFICIENT:
25ppm/
C
q
WIDE VOLTAGE COMPLIANCE:
2.5V to 40V
q
ALSO INCLUDES CURRENT MIRROR
APPLICATIONS
q
SENSOR EXCITATION
q
BIASING CIRCUITRY
q
OFFSETTING CURRENT LOOPS
q
LOW VOLTAGE REFERENCES
q
CHARGE-PUMP CIRCUITRY
q
HYBRID MICROCIRCUITS
REF200
DUAL CURRENT SOURCE/CURRENT SINK
DESCRIPTION
The REF200 combines three circuit building-blocks
on a single monolithic chip--two 100
A current
sources and a current mirror. The sections are
dielectrically isolated, making them completely
independent. Also, since the current sources are two-
terminal devices, they can be used equally well as
current sinks. The performance of each section is
individually measured and laser-trimmed to achieve
high accuracy at low cost.
The sections can be pin-strapped for currents of 50
A,
100
A, 200
A, 300
A or 400
A. External circuitry
can be used to obtain virtually any current. These and
many other circuit techniques are shown in the
Applications section of this Data Sheet.
The REF200 is available in plastic 8-pin mini-DIP
and SOIC packages.
I
High
I
High
Substrate
Mirror
In
I
Low
I
Low
Mirror
Out
Mirror
Common
1
2
1
2
8
7
6
5
1
2
3
4
100A
100A
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Internet: http://www.burr-brown.com/ FAXLine: (800) 548-6133 (US/Canada Only) Cable: BBRCORP Telex: 066-6491 FAX: (520) 889-1510 Immediate Product Info: (800) 548-6132
REF200
REF200
REF200
2
SPECIFICATIONS
At T
A
= +25
C, V
S
= 15V, unless otherwise noted.
REF200AP, AU
PARAMETER
CONDITION
MIN
TYP
MAX
UNITS
CURRENT SOURCES
Current Accuracy
0.25
1
%
Current Match
0.25
1
%
Temperature Drift
Specified Temp Range
25
ppm/
C
Output Impedance
2.5V to 40V
20
100
M
3.5V to 30V
200
500
M
Noise
BW = 0.1Hz to 10Hz
1
nAp-p
f = 10kHz
20
pA/
Hz
Voltage Compliance (1%)
T
MIN
to T
MAX
See Curves
Capacitance
10
pF
CURRENT MIRROR
I = 100
A Unless
Otherwise Noted
Gain
0.995
1
1.005
Temperature Drift
25
ppm/
C
Impedance (output)
2V to 40V
40
100
M
Nonlinearity
I = 0
A to 250
A
0.05
%
Input Voltage
1.4
V
Output Compliance Voltage
See Curves
Frequency Response (3dB)
Transfer
5
MHz
TEMPERATURE RANGE
Specification
25
+85
C
Operating
40
+85
C
Storage
40
+125
C
ELECTRICAL
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user's own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
Applied Voltage ..................................................................... 6V to +40V
Reverse Current ........................................................................... 350
A
Voltage Between Any Two Sections .................................................
80V
Operating Temperature ................................................... 40
C to +85
C
Storage Temperature ..................................................... 40
C to +125
C
Lead Temperature (soldering, 10s) .............................................. +300
C
(SOIC 3s) ........................................................ +260
C
I
I
Substrate
Mirror Input
Low
Low
Mirror Common
Mirror Output
1
2
3
4
8
7
6
5
1
2
High
High
1
2
I
I
Top View
DIP/SOIC
PACKAGE
DRAWING
TEMPERATURE
PRODUCT
PACKAGE
NUMBER
(1)
RANGE
REF200AP
8-Pin Plastic DIP
006
25
C to +85
C
REF200AU
8-Pin SOIC
182
25
C to +85
C
NOTE: (1) For detailed drawing and dimension table, please see end of data
sheet, or Appendix C of Burr-Brown IC Data Book. (2) Grade designation "A"
may not be marked. Absence of grade designation indicates A grade.
PACKAGE/ORDERING INFORMATION
ELECTROSTATIC
DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
ESD damage can range from subtle performance degradation
to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric
changes could cause the device not to meet its published
specifications.
REF200
3
TYPICAL PERFORMANCE CURVES
At T
A
= +25
C, V
S
= +15V, unless otherwise noted.
100.1
100
99.9
99.8
99.7
99.6
99.5
25
50
25
75
50
125
100
0
Temperature (C)
Current (A)
85C
Drift specified by
"box method"
(See text)
CURRENT SOURCE
TYPICAL DRIFT vs TEMPERATURE
600
500
400
300
200
100
0
5
0
10
Temperature Drift (ppm/C)
Quantity (Units)
Distribution of three
production lots --
1284 Current Sources.
20
15
25
35
30
40
50
45
55
65
60
2
5
117
30
15
6
0
1
1
501
454
86
66
CURRENT SOURCE
TEMPERATURE DRIFT DISTRIBUTION
101
100.8
100.6
100.4
100.2
100
99.8
99.6
99.4
99.2
Current (A)
99
0
5
10
15
20
25
30
35
40
Voltage (V)
CURRENT SOURCE
OUTPUT CURRENT vs VOLTAGE
CURRENT SOURCE
OUTPUT CURRENT vs VOLTAGE
0
100.5
100.4
100.3
100.2
100.1
100
99.9
99.8
99.7
99.6
99.5
Voltage (V)
1
2
3
4
5
Current (A)
55C
25C
125C
1000
900
800
700
600
500
400
300
200
100
Reverse Current (A)
0
0
2
4
6
8
10
12
Reverse Voltage (V)
CURRENT SOURCE
REVERSE CURRENT vs REVERSE VOLTAGE
Reverse Voltage
Circuit Model
12k
7V
5k
Safe Reverse Current
Safe Reverse Voltage
Output Current (500pA/div)
CURRENT SOURCE
CURRENT NOISE (0.1Hz to 10Hz)
Time (500ms/div)
REF200
4
TYPICAL PERFORMANCE CURVES
(CONT)
At T
A
= +25
C, V
S
= +15V, unless otherwise noted.
MIRROR TRANSFER NONLINEARITY
0
0.1
0.08
0.06
0.04
0.02
0
0.02
0.04
0.06
0.08
0.01
Current (A)
50
100
150
200
250
Nonlinearity (% of 250A)
Data from Three
Representative Units
(Least-square fit)
5
4
3
2
1
0
1
2
3
4
Error (%)
5
10A
100A
1mA
Mirror Current (A)
MIRROR GAIN ERROR vs CURRENT
V =
1.25V
V = 1V
V = 1.5V
O
O
O
Input Voltage (V)
0
1A
10A
100A
1mA
10mA
Current
MIRROR INPUT VOTAGE/OUTPUT
COMPLIANCE VOLTAGE vs CURRENT
4
3
2
1
Input Voltage
Output
Compliance
Voltage
REF200
5
FIGURE 1. Simplified Circuit Diagram.
(Substrate)
Current
Source
(1 of 2)
4k
8X
8,7
5k
1k
1,2
6
3
5
4
1k
12k
Current
Mirror
APPLICATIONS INFORMATION
The three circuit sections of the REF200 are electrically
isolated from one another using a dielectrically isolated
fabrication process. A substrate connection is provided (pin
6), which is isolated from all circuitry. This pin should be
connected to a defined circuit potential to assure rated DC
performance. The preferred connection is to the most nega-
tive constant potential in your system. In most analog
systems this would be V
S
. For best AC performance, leave
pin 6 open and leave unused sections unconnected.
Drift performance is specified by the "box method," as
illustrated in the Current vs Temperature plot of the typical
performance curves. The upper and lower current extremes
measured over temperature define the top and bottom of the
box. The sides are determined by the specified temperature
range of the device. The drift of the unit is the slope of the
diagonal--typically 25ppm/
C from 25
C to +85
C.
If the current sources are subjected to reverse voltage, a
protection diode may be required. A reverse voltage circuit
model of the REF200 is shown in the Reverse Current vs
Reverse Voltage curve. If reverse voltage is limited to less
than 6V or reverse current is limited to less than 350
A, no
protection circuitry is required. A parallel diode (Figure 2a)
will protect the device by limiting the reverse voltage across
the current source to approximately 0.7V. In some applica-
tions, a series diode may be preferable (Figure 2b) because
it allows no reverse current. This will, however, reduce the
compliance voltage range by one diode drop.
Applications for the REF200 are limitless. Application Bul-
letin AB-165 shows additional REF200 circuits as well as
other related current source techniques. A collection of
circuits is shown to illustrate some techniques. Also, see
AB-165A.
FIGURE 2. Reverse Voltage Protection.
100A
Bidirectional
Current Source
D
4
D
2
D
D
3
1
D
2
D
1
100A
100A
NOTE: All diodes = 1N4148.
Bidirectional
Current Source
(a)
(b)
(c)
(d)
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