TSM9634 [TOUCHSTONE]
A 1uA, SOT23 Precision Current-Sense Amplifier; 一个1uA，这SOT23高精度电流检测放大器
| 型号： | TSM9634 |
| 厂家： | 
TOUCHSTONE SEMICONDUCTOR INC |
| 描述： | A 1uA, SOT23 Precision Current-Sense Amplifier |
| 文件： | 总11页 (文件大小：742K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
TSM9634
A 1µA, SOT23 Precision Current-Sense Amplifier
DESCRIPTION
FEATURES
♦ Alternate-source for MAX9634
♦ Ultra-Low Supply Current: 1μA
♦ Wide Input Common Mode Range: +1.6V to +28V
♦ Low Input Offset Voltage: 250µV (max)
♦ Low Gain Error: <0.5% (max)
♦ Voltage Output
The
voltage-output
TSM9634
current-sense
amplifiers are electrically and form-factor identical to
the MAX9634 current-sense amplifiers. Consuming a
very low 1μA supply current, the TSM9634 high-side
current-sense amplifiers exhibit a 250-µV (max) VOS
and a 0.5% (max) gain error, both specifications
optimized for any precision current measurement. For
all high-side current-sensing applications, the
TSM9634 features a wide input common-mode
voltage range from 1.6V to 28V.
♦ Four Gain Options Available:
TSM9634T: Gain = 25V/V
TSM9634F: Gain = 50V/V
TSM9634H: Gain = 100V/V
TSM9634W: Gain = 200V/V
♦ 5-Pin SOT23 Packaging
The SOT23 package makes the TSM9634 an ideal
choice for pcb-area-critical, low-current, high-
accuracy current-sense applications in all battery-
powered portable instruments.
APPLICATIONS
Notebook Computers
Power Management Systems
Portable/Battery-Powered Systems
PDAs
All TSM9634s are specified for operation over the
-40°C to +85°C extended temperature range.
Smart Chargers
Smart Phones
TYPICAL APPLICATION CIRCUIT
Input Offset Voltage Histogram
35
30
25
20
15
10
5
0
10
20
30
40
0
50
INPUT OFFSET VOLTAGE - µV
PART
GAIN OPTION
25 V/V
TSM9634T
TSM9634F
TSM9634H
TSM9634W
50 V/V
100 V/V
200 V/V
The Touchstone Semiconductor logo is a registered
trademark of Touchstone Semiconductor, Incorporated.
Page 1
© 2011 Touchstone Semiconductor, Inc. All rights reserved.
TSM9634
ABSOLUTE MAXIMUM RATINGS
RS+, RS- to GND..............................................-0.3V to +30V
OUT to GND........................................................-0.3V to +6V
RS+ to RS-..................................................................... ±30V
Short-Circuit Duration: OUT to GND .................... Continuous
Continuous Input Current (Any Pin) ............................ ±20mA
Continuous Power Dissipation (TA = +70°C)
Operating Temperature Range ...................... -40°C to +85°C
Junction Temperature ................................................ +150°C
Storage Temperature Range ....................... -65°C to +150°C
Lead Temperature (Soldering, 10s) ........................... +300°C
Soldering Temperature (Reflow) ............................ +260°C
5-Pin SOT23 (Derate at 3.9mW/°C above +70°C).. 312mW
Electrical and thermal stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These
are stress ratings only and functional operation of the device at these or any other condition beyond those indicated in the operational sections
of the specifications is not implied. Exposure to any absolute maximum rating conditions for extended periods may affect device reliability and
lifetime.
PACKAGE/ORDERING INFORMATION
ORDER NUMBER
TSM9634TEUK+TP
TSM9634TEUK+T
TSM9634FEUK+TP
TSM9634FEUK+T
TSM9634HEUK+TP
TSM9634HEUK+T
TSM9634WEUK+TP
TSM9634WEUK+T
PART MARKING
TADD
CARRIER
QUANTITY
-----
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel
Tape & Reel
3000
-----
TADB
TADE
TADG
3000
-----
3000
-----
3000
Lead-free Program: Touchstone Semiconductor supplies only lead-free packaging.
Consult Touchstone Semiconductor for products specified with wider operating temperature ranges.
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TSM9634DS r1p0
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TSM9634
ELECTRICAL CHARACTERISTICS
VRS+ = VRS- = 3.6V; VSENSE = (VRS+ - VRS-) = 0V; TA = -40°C to +85°C, unless otherwise noted. Typical values are at
TA = +25°C. See Note 1
PARAMETER
SYMBOL
CONDITIONS
VRS+ = 5V, TA = +25°C
VRS+ = 5V, -40°C < TA < +85°C
VRS+ = 28V, TA = +25°C
MIN
TYP
0.5
MAX
0.85
1.1
UNITS
Supply Current (Note 2)
ICC
μA
1.1
1.8
VRS+ = 28V, -40°C < TA < +85°C
Guaranteed by CMRR , -40°C < TA < +85°C
2.5
28
Common-Mode Input Range
Common-Mode Rejection
Ratio
VCM
1.6
94
V
CMRR
1.6V < VRS+ < 28V, -40°C < TA < +85°C
130
100
dB
TA = +25°C
-40°C < TA < +85°C
TA = +25°C
250
300
250
425
TSM9634T/TSM9634F/
TSM9634H
μV
μV
Input Offset Voltage (Note 3)
VOS
100
TSM9634W
-40°C < TA < +85°C
TSM9634T
TSM9634F
25
50
Gain
G
V/V
TSM9634H
TSM9634W
TSM9634T/TSM9634F/
TSM9634H
100
200
±0.1
TA = +25°C
-40°C < TA < +85°C
TA = +25°C
-40°C < TA < +85°C
TSM9634T/F/H
TSM9634W
±0.5
±0.6
±0.7
±0.8
13.2
26.4
7.5
15
30
85
0.2
Gain Error (Note 4)
Output Resistance
GE
%
±0.1
TSM9634W
(Note 5)
7.0
14.0
10
20
1.5
3
6
12
0.1
ROUT
kΩ
Gain = 25
Gain = 50
Gain = 100
Gain = 200
OUT Low Voltage
OUT High Voltage
VOL
VOH
mV
V
VOH = VRS- - VOUT (Note 6)
Note 1: All devices are 100% production tested at TA = +25°C. All temperature limits are guaranteed by product
characterization.
Note 2: Extrapolated to VOUT = 0. ICC is the total current into the RS+ and the RS- pins.
Note 3: Input offset voltage VOS is extrapolated from VOUT with VSENSE set to 1mV.
Note 4: Gain error is calculated by applying two values for VSENSE and then calculating the error of the actual slope vs. the
ideal transfer characteristic:
For GAIN = 25, the applied VSENSE is 20mV and 120mV.
For GAIN = 50, the applied VSENSE is 10mV and 60mV.
For GAIN = 100, the applied VSENSE is 5mV and 30mV.
For GAIN = 200, the applied VSENSE is 2.5mV and 15mV.
Note 5: The device is stable for any capacitive load at VOUT
.
Note 6: VOH is the voltage from VRS- to VOUT with VSENSE = 3.6V/GAIN.
TSM9634DS r1p0
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TSM9634
TYPICAL PERFORMANCE CHARACTERISTICS
VRS+ = VRS- = 3.6V; TA = +25°C, unless otherwise noted.
Gain Error Histogram
Input Offset Voltage Histogram
35
30
30
25
20
15
10
25
20
15
10
5
5
0
0
-0.4
-0.2
0
0.2
0.4
10
20
30
40
50
0
GAIN ERROR - %
INPUT OFFSET VOLTAGE - µV
Input Offset Voltage vs Common-Mode Voltage
Supply Current vs Temperature
40
1
28V
0.8
0.6
0.4
0.2
0
35
30
25
20
1.8V
3.6V
-40
-15
10
35
60
85
0
5
10
20
25
30
15
SUPPLY VOLTAGE - Volt
TEMPERATURE - °C
Supply Current vs Common-Mode Voltage
Input Offset Voltage vs Temperature
80
60
1
0.8
0.6
0.4
0.2
0
40
20
0
-20
-40
-15
35
60
85
0
5
10
20
25
30
10
15
SUPPLY VOLTAGE - Volt
TEMPERATURE - °C
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TSM9634DS r1p0
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TSM9634
TYPICAL PERFORMANCE CHARACTERISTICS
VRS+ = VRS- = 3.6V; TA = +25°C, unless otherwise noted.
Gain Error vs Common-Mode Voltage
Gain Error vs. Temperature
0.5
0.4
0.3
0.2
0.3
0.2
0.1
0
0.1
0
-0.1
0
5
10
15
20
25
30
-40
-15
10
35
60
85
SUPPLY VOLTAGE - Volt
TEMPERATURE - °C
VOUT vs VSENSE @ Supply = 3.6V
VOUT vs VSENSE @ Supply = 1.6V
4
3.5
3
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
G = 100
G = 50
G = 100
G = 50
2.5
2
G = 25
G = 25
1.5
1
0.5
0
0
50
100
150
0
100
20
40
60
80
VSENSE - mV
VSENSE - mV
Common-Mode Rejection vs Frequency
Small-Signal Gain vs Frequency
5
0
0
-20
-40
-60
-80
-100
G = 50
G = 50, 100
-5
G = 100
G = 25
-10
-15
-20
-25
G = 25
-120
-140
-30
-35
0.001 0.01 0.1
10
100 1000
1
0.001 0.01 0.1
1
10
100 1000
FREQUENCY - kHz
FREQUENCY - kHz
TSM9634DS r1p0
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TSM9634
TYPICAL PERFORMANCE CHARACTERISTICS
VRS+ = VRS- = 3.6V; TA = +25°C, unless otherwise noted.
Large-Signal Pulse Response, Gain = 50
Small-Signal Pulse Response, Gain = 50
200µs/DIV
200µs/DIV
Large-Signal Pulse Response, Gain = 25
Small-Signal Pulse Response, Gain = 25
200µs/DIV
200µs/DIV
Small-Signal Pulse Response, Gain = 100
Large-Signal Pulse Response, Gain = 100
200µs/DIV
200µs/DIV
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TSM9634
PIN FUNCTIONS
PIN
SOT23
LABEL
FUNCTION
5
4
1, 2
3
RS+
RS-
GND
OUT
External Sense Resistor Power-Side Connection
External Sense Resistor Load-Side Connection
Ground. Connect these pins to analog ground.
Output Voltage. VOUT is proportional to VSENSE = VRS+ - VRS-
BLOCK DIAGRAMS
DESCRIPTION OF OPERATION
The internal configuration of the TSM9634 – a
unidirectional high-side, current-sense amplifier - is
based on a commonly-used operational amplifier (op
amp) circuit for measuring load currents (in one
direction) in the presence of high-common-mode
voltages. In the general case, a current-sense
amplifier monitors the voltage caused by a load
current through an external sense resistor and
generates an output voltage as a function of that load
current. Referring to the typical application circuit on
Page 1, the inputs of the op-amp-based circuit are
connected across an external RSENSE resistor that
is used to measure load current. At the non-inverting
input of the TSM9634 (the RS+ terminal), the applied
voltage is ILOAD x RSENSE. Since the RS- terminal is
the non-inverting input of the internal op amp, op-amp
feedback action forces the inverting input of the
internal op amp to the same potential
RSENSE (VSENSE) and the voltage drop across R1 (at
the RS+ terminal) are equal. To minimize any
additional error because of op-amp input bias current
mismatch, both R1s are the same value.
Since the internal p-channel FET’s source is
connected to the inverting input of the internal op
amp and since the voltage drop across R1 is the
same as the external VSENSE, op amp feedback action
drives the gate of the FET such that the FET’s drain-
source current is equal to:
VSENSE
ꢀꢁS
ꢂ
R1
(ILOAD x RSENSE). Therefore, the voltage drop across
TSM9634DS r1p0
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TSM9634
or
stage is protected against input overdrive by use of
an output current-limiting circuit of 3mA (typical) and
a 7V internal clamp protection circuit.
ꢀLOAꢁ x RSENSE
ꢀꢁS
ꢂ
R1
Table 1: Internal Gain Setting Resistors (Typical
Values)
Since the FET’s drain terminal is connected to
ROUT, the output voltage of the TSM9634 at the
OUT terminal is, therefore;
GAIN (V/V) R1 (Ω) ROUT (Ω) Part Number
ROUT
25
50
100
200
400
200
100
100
10k
10k
10k
20k
TSM9634T
TSM9634F
TSM9634H
TSM9634W
VOUT ꢂ ꢀLOAꢁ x RSENSE
x
R1
The current-sense amplifier’s gain accuracy is
therefore the ratio match of ROUT to R1. For each of
the four gain options available, Table 1 lists the
values for ROUT and R1. The TSM9634’s output
APPLICATIONS INFORMATION
and
Choosing the Sense Resistor
VOUT ꢀmaxꢁ
RSENSE
ꢂ
Selecting the optimal value for the external RSENSE
is based on the following criteria and for each
commentary follows:
GAꢀN ꢃ ꢀLOAꢁꢀmaxꢁ
where the full-scale VSENSE should be less than
VOUT(MAX)/GAIN at the application’s minimum RS+
terminal voltage. For best performance with a 3.6V
power supply, RSENSE should be chosen to
generate a VSENSE of: a) 120mV (for the 25V/V GAIN
option), b) 60mV (for the 50V/V GAIN option), c)
30mV (for the 100V/V GAIN option), or d) 15mV (for
the 200V/V GAIN option) at the full-scale ILOAD(MAX)
current in each application. For the case where the
minimum power supply voltage is higher than 3.6V,
each of the four full-scale VSENSEs above can be
increased.
1) RSENSE Voltage Loss
2) VOUT Swing vs. Applied Input Voltage at VRS+
and Desired VSENSE
3) Total ILOAD Accuracy
4) Circuit Efficiency and Power Dissipation
5) RSENSE Kelvin Connections
1) RSENSE Voltage Loss
For lowest IR voltage loss in RSENSE, the smallest
usable value for RSENSE should be selected.
3) Total ILOAD Accuracy
2) VOUT Swing vs. Applied Input Voltage at VRS+
and Desired VSENSE
In the TSM9634’s linear region where
VOUT < VOUT(max), there are two specifications related
to the circuit’s accuracy: a) the TSM9634’s input
offset voltage (VOS = 250μV, max) and b) its gain
error (GE(max) = 0.5%). An expression for the
TSM9634’s total output voltage (+ error) is given by:
As there is no separate power supply pin for the
TSM9634, the circuit draws its power from the
applied voltage at both its RS+ and RS- terminals.
Therefore, the signal voltage at the OUT terminal is
bounded by the minimum supply voltage applied to
the TSM9634.
VOUT = [GAIN x (1 ± GE) x VSENSE] ± (GAIN x VOS)
Therefore,
A large value for RSENSE permits the use of smaller
load currents to be measured more accurately
because the effects of offset voltages are less
significant when compared to larger VSENSE voltages.
Due care though should be exercised as
VOUT(max) = VRS+(min) - VSENSE(max) – VOH(max)
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TSM9634DS r1p0
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TSM9634
previously mentioned with large values of RSENSE.
between RSENSE and the TSM9634’s RS+ and RS-
terminals are strongly recommended. The drawing in
Figure 1 illustrates the connections between the
current-sense amplifier and the current-sense
resistor. The pcb layout should be balanced and
symmetrical to minimize wiring-induced errors. In
addition, the pcb layout for RSENSE should include
good thermal management techniques for optimal
RSENSE power dissipation.
4) Circuit Efficiency and Power Dissipation
IR losses in RSENSE can be large especially at high
load currents. It is important to select the smallest,
usable RSENSE value to minimize power dissipation
and to keep the physical size of RSENSE small. If
the external RSENSE is allowed to dissipate
significant power, then its inherent temperature
coefficient may alter its design center value, thereby
reducing load current measurement accuracy.
Precisely because the TSM9634’s input stage was
designed to exhibit a very low input offset voltage,
small RSENSE values can be used to reduce power
dissipation and minimize local hot spots on the pcb.
Optional Output Filter Capacitor
If the TSM9634 is part of a signal acquisition system
where its OUT terminal is connected to the input of
an ADC with an internal, switched-capacitor track-
and-hold circuit, the internal track-and-hold’s
sampling capacitor can cause voltage droop at VOUT
A 22nF to 100nF good-quality ceramic capacitor
from the OUT terminal to GND should be used to
minimize voltage droop (holding VOUT constant
during the sample interval. Using a capacitor on the
OUT terminal will also reduce the TSM9634’s small-
signal bandwidth as well as band-limiting amplifier
noise.
.
5) RSENSE Kelvin Connections
For optimal VSENSE accuracy in the presence of large
load currents, parasitic pcb track resistance should
be minimized. Kelvin-sense pcb connections
Using the TSM9634 in Bidirectional Load Current
Applications
In many battery-powered systems, it is oftentimes
necessary to monitor a battery’s discharge and
charge currents. To perform this function, a
bidirectional current-sense amplifier is required. The
circuit illustrated in Figure 2 shows how two
TSM9634s can be configured as a bidirectional
current-sense amplifier. As shown in the figure, the
Figure 1: Making PCB Connections to the Sense
Resistor (drawing is not to scale).
Figure 2: Using Two TSM9634s for Bidirectional Load Current Detection
TSM9634DS r1p0
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TSM9634
RS+/RS- input pair of TSM9634 #2 is wired opposite
in polarity with respect to the RS+/RS- connections
of TSM9634 #1. Current-sense amplifier #1
therefore measures the discharge current and
current-sense amplifier #2 measures the charge
current. Note that both output voltages are
measured with respect to GND. When the discharge
current is being measured, VOUT1 is active and VOUT2
is zero; for the case where charge current is being
measured, VOUT1 is zero, and VOUT2 is active.
PC Board Layout and Power-Supply Bypassing
For optimal circuit performance, the TSM9634
should be in very close proximity to the external
current-sense resistor and the pcb tracks from
RSENSE to the RS+ and the RS- input terminals of
the TSM9634 should be short and symmetric. Also
recommended are a ground plane and surface
mount resistors and capacitors.
Page 10
TSM9634DS r1p0
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TSM9634
PACKAGE OUTLINE DRAWING
5-Pin SOT23 Package Outline Drawing
(N.B., Drawings are not to scale)
NOTES:
1. Dimensions and tolerances are as per ANSI Y14.5M, 1982.
2. Package surface to be matte finish VDI 11~13.
5
2.80 - 3.00
3. Die is facing up mold and facing down for trim/form,
ie, reverse trim/form.
0.950
0.95
TYP
TYP
4. The foot length measuring is based on the gauge plane method.
5.Dimensions are exclusive of mold flash and gate burr.
6. Dimensions are exclusive of solder plating.
7. All dimensions are in mm.
8. This part is compliant with EIAJ spec. and JEDEC MO-178 AA
0.30 - 0.50
9. Lead span/stand off height/coplanarity are considered as special
characteristic.
1.90 Max
10º TYP
1.50 – 1.75
10º TYP
0.09 – 1.45
0.60 – 0.80
0.90 - 1.30
0º- 8º
0.25
0.00 - 0.15
0.09 - 0.20
5
0.30 - 0.55
Gauge Plane
10º TYP
10º TYP
0.10 Max
0.50 – 0.70
0.50 Max
0.30 Min
0.20 Max
0.09 Min
Information furnished by Touchstone Semiconductor is believed to be accurate and reliable. However, Touchstone Semiconductor does not
assume any responsibility for its use nor for any infringements of patents or other rights of third parties that may result from its use, and all
information provided by Touchstone Semiconductor and its suppliers is provided on an AS IS basis, WITHOUT WARRANTY OF ANY KIND.
Touchstone Semiconductor reserves the right to change product specifications and product descriptions at any time without any advance
notice. No license is granted by implication or otherwise under any patent or patent rights of Touchstone Semiconductor. Touchstone
Semiconductor assumes no liability for applications assistance or customer product design. Customers are responsible for their products and
applications using Touchstone Semiconductor components. To minimize the risk associated with customer products and applications,
customers should provide adequate design and operating safeguards. Trademarks and registered trademarks are the property of their
respective owners.
Touchstone Semiconductor, Inc.
Page 11
630 Alder Drive, Milpitas, CA 95035
+1 (408) 215 - 1220 ▪ www.touchstonesemi.com
TSM9634DS r1p0
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