DC1698A - Demo Manual

DEMO MANUAL DC1698A
LT1999: High Voltage,
Bidirectional Current
Sense Amplifier
DESCRIPTION
Demonstration circuit 1698A features the LT1999, a high
voltage, bi-directional current sense amplifier.
The demo board amplifies the voltage drop across an on
board current sense resistor. The output voltage is a bidirectional signal that is centered on the VREF voltage and
is proportional to the current through the sense resistor.
The output is scaled by one of three fixed gain options. The
gain options are: 10V/V (DC1698A-A), 20V/V (DC1698A-B)
and 50V/V (DC1698A-C). The input voltage range is from
–5V to 80V (independent of the device supply voltage)
allowing the part to be used for high or low side current
sensing. The LT1999 requires a separate 5V supply voltage.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
PERFORMANCE SUMMARY
Table 1. Performance Summary (TA = 25°C)
SYMBOL
PARAMETER
VS
Supply Range
4.5
5.5
V
VCM
CM Input Voltage Range
–5
80
V
CMRR
Common Mode Rejection Ratio
VCM = 0V , 7VP-P, f = 100kHz
VOUT
Swing Output High (with Respect to V+)
Swing Output Low (with Respect to V–)
RLOAD = Open
RLOAD = Open
VOSI
Input Referred Offset Voltage
TA = 25°C, VCM > 5.5V
550
μV
IQ
V+ Quiescent Current
VCM > 5.5V
1.55
mA
VREF
Open Circuit Voltage
VS = 5V
VREFIN
CONDITIONS
REF Pin Input Range
MIN
80
TYP
100
5
150
2.44
1.25
MAX
2.5
UNITS
dB
125
225
mV
mV
2.55
V
V+ – 1.5
V
OPERATING PRINCIPLES
The LT1999 operates by amplifying the voltage drop
across a user selected sense resistor. The voltage across
the resistor is amplified by a fixed gain of 10V/V, 20V/V
or 50V/V(LT1999-10,LT1999-20,LT1999-50) and is level
shifted to the OUT pin of the device. The voltage difference
and polarity with respect to the VREF pin voltage indicates
the magnitude and direction of the current in the sense
resistor.
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DEMO MANUAL DC1698A
BLOCK DIAGRAM
V+
2μA
V+
4.5k
SHDN
1
V(G+IN)
R +IN
2
+IN
V(G–IN)
2k
2k
CF
4pF
3
–IN
2k
2k
0.8k
R +S
0.8k
R –S
R –IN
RG
+
GIN
–
V+
D1
8
–
+ AO
OUT
7
V+
300Ω
160k
REF
6
160k
V+
GND
4
5
LT1999
1999 BD
QUICK START PROCEDURE
Demonstration circuit 1698 is easy to set up and evaluate
the performance of the LT1999. Refer to Figure 1 for proper
measurement equipment setup and follow the procedure:
3. Connect a voltmeter to the VOUT terminal, with the common connected to the VREF terminal. An oscilloscope can
also be used to monitor Vout with respect to ground.
1. With power off, connect a power supply to V+ and the
common to GND. This supply should be between 4.5V
and 5.5V. Connect a second supply’s positive terminal
to the VSENSE+ and connect its common to the circuit
ground. The second supply’s (load supply) output voltage can range from –5V to 80V.
4. Turn on the power supply to the device and the load
supply.
5. Measure the output voltage with respect to VREF. The
output voltage will be proportional to the load and with
the factory set sense resistor will equal 0.5V per 1A.
2. With power off, connect the load to the VSENSE–. If
the load power source does not have accurate current
readout a DMM may be connected in series with the
load as shown in Figure 1.
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DEMO MANUAL DC1698A
QUICK START PROCEDURE
LOAD SUPPLY
(–5V TO 80V)
20V
5.00V
DEVICE SUPPLY
(4.5V TO 5.5V)
1.00V
VOUT
2.00A
LOAD
10Ω
Figure 1. Proper Measurement Equipment Setup
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DEMO MANUAL DC1698A
PARTS LIST
ITEM
QUANTITY
REFERENCE
DESCRIPTION
MANUFACTURER’S PART NUMBER
1
2
C1, C2
Capacitor, 0.1μF 10% 25V X7R 0603
AVX, 06033C104KAT2A
2
1
C3
Capacitor, 100pF 10% 16V X7R 0402
AVX, 0402YC101KAT2A
3
1
R2
Resistor, 0Ω 0603 1% 1/16W
YAGEO, RC0603FR-070RL
1
1
DC1698A
2
1
R1
Resistor, 0.05Ω 1% 2512 2W
SEI, CSRN2512FT50L0
3
1
U1
IC, LT1999IMS8-10
Linear Technology, LT1999IMS8-10#PBF
1
1
DC1698A
2
1
R1
Resistor, 0.025Ω 1% 2512 1W
Vishay, WSL2512R0250FEA
3
1
U1
IC, LT1999IMS8-20
Linear Technology, LT1999IMS8-20#PBF
1
1
DC1698A
2
1
R1
Resistor, 0.01Ω 1W 1% 2512 SMD
Vishay, WSL2512R0100FEA
3
1
U1
IC, LT1999IMS8-50
Linear Technology, LT1999IMS8-50#PBF
General BOM
DC1698A-A
General BOM
DC1698A-B
General BOM
DC1698A-C
General BOM
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V+
E1
E2
1
*
2512
R1
E6
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation
that the interconnection of its circuits as described herein will not infringe on existing patent rights.
1. ALL RESISTORS ARE IN OHMS, 0603
2. ALL CAPACTORS ARE IN MICROFARADS, 0603
NOTES: UNLESS OTHERWISE SPECIFIED
VSENSE -
-5V - +80V
VSENSE +
4.5V - 5.5V
1
1
VSUPPLY
IN-
IN+
VSUPPLY
CUSTOMER NOTICE
0.1uF
C2
4
3
2
1
LT1999IMS8*
U1
THIS CIRCUIT IS PROPRIETARY TO
LINEAR TECHNOLOGY AND SUPPLIED FOR
USE WITH LINEAR TECHNOLOGY PARTS.
R2
0.1uF
C1
0 Ohm
CUYLER L.
APP ENG.
SCALE = NONE
CL
APPROVALS
5
6
7
8
PCB DES.
GND
VREF
VOUT
VSHDN\
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT
TO DESIGN A CIRCUIT THAT MEETS CUSTOMERSUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS
THE CUSTOMER'S RESPONSIBILITY TO VERIFY
PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND
PRINTED CIRCUIT LAYOUT MAY SIGNIFICANTLY
AFFECT CIRCUIT PERFORMANCE OR RELIABILITY.
CONTACT LINEAR TECHNOLOGY APPLICATIONS
ENGINEERING FOR ASSISTANCE.
V+
V+
E5
E4
E3
E7
GND
VREF
2V AT 4A
VOUT
/SHDN
*
-C
-B
-A
ASSY
DATE
10/01/2010
0.01 ohm
0.025 ohm
LTC CONFIDENTIAL FORCUSTOMER USE ONLY
WWW.LINEAR.COM
R1
CUYLER L.
APPR
0.05 ohm
1630 McCarthy Blvd.
Milpitas, CA 95035
PH: (408) 432-1900
LT1999IMS8-50
LT1999IMS8-20
LT1999IMS8-10
U1
PRODUCTION
DESCRIPTION
SIZE
HIGH VOLTAGE BI-DIRECTIONAL CURRENT SENSE
REV
IC NO.
LT1999IMS8-10/-20/-50
1
N/A
DEMO CIRCUIT 1698A
10/2010
DATE:
SH 1 of 1
TITLE: SCHEMATIC
1
1
1
0402
100pF
C3
1
1
ECO REV
DEMO MANUAL DC1698A
SCHEMATIC DIAGRAM
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DEMO MANUAL DC1698A
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
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Linear Technology Corporation
LT 0911 REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2011
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