TI UCC2926

application
INFO
available
± 20A Integrated Current Sensor
UCC1926
UCC2926
UCC3926
FEATURES
DESCRIPTION
• Integral Non-inductive Current Sense
Element with Internal Kelvin
Connections
The UCC3926 Current Sensor IC contains a wideband, transimpedance
amplifier for converting the current through an internal, non-inductive
1.3mΩ shunt resistor into a proportional voltage. The sense element operates in both high-side (VDD referenced) and low-side (GND referenced) applications.
• 20A Current Rating
• Bi-directional, High Side or Low Side
Sensing
• Internal Temperature Nulling Circuitry
for Current Sense Element and
Amplifier
• Logic Compatible Current Direction
Status Output
• Low Offset, Chopper Stabilized
Current Sense Amplifier
• Uncommitted Amplifier with User
Programmable Gain
• Overcurrent Indication with User
Programmable Threshold
The UCC3926 can measure currents up to ±20A. This transimpedance amplifier gain is precisely trimmed to 33.3mΩ to convert a 15A input into a
500mV output signal. It has a very low input offset voltage from chopper-stabilization. A cross-switching block rectifies the input signal by forcing
the differential output, AOP positive with respect to the other differential
output, AON. SIGN indicates the polarity of the current.
The UCC3926 programmable amplifier provides three functions. It converts
the differential transimpedance output signal into a single-ended signal. It
has a user-controlled gain stage that sets the maximum current level to the
desired voltage and it level shifts the zero current point to the desired level
as well. A comparator then compares the output of the instrumentation amplifier to a user-set reference voltage on OCREF, which provides an
overcurrent status bit OC.
The UCC3926 is available in the 16 pin SOIC package.
BLOCK DIAGRAM
UDG-97139-1
SLUS266A - OCTOBER 1999
UCC1926
UCC2926
UCC3926
CONNECTION DIAGRAM
ABSOLUTE MAXIMUM RATINGS
Input Sense Current (IIN) . . . . . . . . . . . . . . . . . . . . . . . . . ± 20A
Supply Voltage, VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.5V
Inrush Current, 50µs . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±100A
Input Voltage Range (CSP, CSN) . . . . . . . . . . . –0.2V to 14.5V
CSP, CSN, Common Mode Range
(referenced to GND) . . . . . . . . . . . . . . . . . . . . . . . . . ± 200mV
CSP, CSN, Common Mode Range
(referenced to VDD) . . . . . . . . . . . . . . . . . . . . . . . . . . ± 200mV
Shunt Resistance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.25mΩ
Storage Temperature . . . . . . . . . . . . . . . . . . . . –65°C to 150°C
Junction Temperature . . . . . . . . . . . . . . . . . . . . –55°C to 150°C
Lead Temperature (Soldering, 10sec.) . . . . . . . . . . . . . . 300°C
SOIC-16 (Top View)
DS Package
Currents are positive into, negative out of the specified terminal. Consult Packaging Section of Databook for thermal limitations and considerations of packages.
ORDERING INFORMATION
TEMPERATURE RANGE
PACKAGES
UCC1926
– 55°C to +125°C
DS
UCC2926
– 40°C to +85°C
DS
UCC3926
0°C to +70°C
DS
ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for VDD = 4.8V; all temperature
ranges and TA = TJ.
PARAMETER
Supply Section
VDD
IVDD
Transimpedance Amplifier Section
AOP – AON
Quiescent Output Voltage (AOP, AON)
Quiescent Differential Voltage (AOP –
AON)
Bandwidth
Output Impedance
Shunt Resistance
PSRR
Temperature Coefficient
Sign Comparator Section
VOH, VDD – SIGN
VOL, SIGN
IIH Threshold
IIL Threshold
Programmable Amplifier Section
AVOL
GBW
VIO
TEST CONDITIONS
MIN
TYP
MAX
UNITS
3.8
14
6
V
mA
510
520
540
590
mV
mV
mV
mV
V
mV
4.8
IIN = 15A, VDD = 10V, 25°C
IIN = 15A, VDD = 10V, 0°C to +70°C
IIN = 15A, VDD = 10V, –40°C to +85°C
IIN = 15A, VDD = 10V, –55°C to +125°C
IIN = 0
IIN = 0, Measure AC Peak to Peak
490
480
460
410
(Note 1)
20
CSP to CSN
VDD = 4.8V to 10V
VDD = 10V to 14V
(Note 1)
2
40
350
1.3
45
25
–200
CSP = 1A, ISIGN = –100µA, CSN = 0V
CSP = –1A, ISIGN = 100µA, CSN = 0V
Ramp CSP, CSN = 0V
Ramp CSP, CSN = 0V
At 200kHz
VIN = 0.5V, 1.5V, 2.5V
500
500
500
500
1.0
0
0.2
0.2
400
–400
60
6
–9
30
500
MHz
Ω
mΩ
dB
dB
200
ppm/°C
0.4
0.4
700
–700
V
V
mA
mA
9
dB
MHz
mV
70
13
UCC1926
UCC2926
UCC3926
ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for VDD = 4.8V; all temperature
ranges and TA = TJ.
PARAMETER
Programmable Amplifier Section (cont.)
PSRR
Common Mode Input Range
IIB, Input Bias Current (NI, INV)
IIO, Input Offset Current
VOL
VOH
VOH, Clamp
IOL
IOH
Overcurrent Comparator Section
OC Comp Threshold
Common Mode Range
Hysteresis
VOL
VOH, VDD – OC
Propagation Delay
TEST CONDITIONS
MIN
VDD = 4.8V to 10V
VDD = 10V to 14V
TYP
60
60
0.5
INV – NI = 20mV, IO = 0µA
INV – NI = 20mV, IO = 200µA
NI – INV = 20mV, IO = –200µA, (VDD – OUT)
NI – INV = 20mV, VDD = 14V
OUT = 1.5V
OUT = 1.5V
6
1
– 250
OCREF = 2V
(Note 1)
2.00
0.1
20
(OCREF – OUT) = 100mV, IOC = 100µA
(OUT – OCREF) = 100mV, IOC = –100µA
(OUT – OCREF) = ± 100mV
–100
20
100
150
1.2
7
3.5
– 325
40
0.2
0.2
90
MAX
UNITS
2.5
–350
350
200
300
2
8
dB
dB
V
nA
nA
mV
mV
V
V
mA
µA
2.05
VDD–
2
60
0.4
0.4
175
V
V
mV
V
V
ns
Note 1: Guaranteed by design. Not 100% tested in prodcution.
PIN DESCRIPTIONS
sensing or to VDD for high side sensing. CSP – CSN
may vary from ±75mV from either GND or VDD. Current
into CSN is defined as negative.
AOP: Positive output of the converted current signal.
Voltage from AOP to AON is the absolute value of the
transimpedance amplifier output. AOP may show some
“chopping” noise. The differential to single-ended
conversion removes the common-mode noise between
AOP and AON.Some high frequency filtering of AOP to
GND can reduce the fast transient spikes. The output
stage of AOP is shown in Figure 1.
CSP: Input connection to the other end of the internal
current sense shunt resistor. Nominal resistance from
CSP to CSN is 1.3mW. The current shunt has a nominal
temperature coefficient of 3530 ppm/°C. The temperature
adjusted autozero gain should cancel this temp co. effect.
CSP may be referenced to GND for low side sensing or
to VDD for high side sensing. CSP – CSN may vary from
±75mV from either GND or VDD. Current into CSP is
defined as positive.
AON: Negative output of the converted current signal.
Voltage from AOP to AON is the absolute value of the
transimpedance amplifier output. AON may show some
“chopping” noise. The differential to single-ended
conversion removes the common-mode noise between
AOP and AON. Some high frequency filtering of AON to
GND can reduce the fast transient spikes. Note that AON
is above GND voltage. The output stage of AON is shown
in Figure 1.
VDD
CROSS SWITCH
IMPEDANCE
CSN: Input connection to one end of the internal current
sense shunt resistor. Nominal resistance from CSP to
CSN is 1.3mΩ. The current shunt has a nominal
temperature coefficient of 3530 ppm/°C. The temperature
adjusted autozero gain is designed to cancel this temp
co. effect. CSN may be referenced to GND for low side
AOP, AON
100
15K
250µA
ESD DIODE
Figure 1. AOP and AON output stage.
3
UCC1926
UCC2926
UCC3926
PIN DESCRIPTIONS (cont.)
Use this opamp to establish overall gain and nominal
zero current reference voltage. This amplifier may be
configured with a gain of one or more. Any non-common
mode “chopping” noise between AOP and AON will show
up at OUT. Some filtering of OUT may improve the application’s performance.
GND: This pin is the return point for all device currents.
INV: Negative input to the programmable amplifier to
provide differential to single-ended signal conversion.
NI: Positive input to the programmable amplifier to
provide differential to single-ended signal conversion.
OC: Overcurrent comparator output. When OUT is
greater than OCREF, OC switches high. The OC
comparator has a typical hysteresis of 25mV.
OCREF: The reference pin of overcurrent comparator for
setting overcurrent threshold voltage.
SIGN: Sign comparator output. SIGN also controls the
analog switches in the cross-switching block to keep
AOP greater than AON. At currents near zero amps, the
sign comparator may switch from “chopping” noise from
the transimpedance amplifier.
OUT: Output of the programmable amplifier intended to
provide differential to single-ended signal conversion of
the transimpedance amplifier's outputs.
VDD: VDD is the power input connection for this device.
Its input range is from 4.8V to 14V. Bypass to GND using
good quality ceramic capacitors.
TYPICAL CHARACTERISTICS CURVES
700
QUIESCENT OUTPUT VOLTAGE [V]
1.4
600
OUTPUT [mV]
500
400
300
200
LIMIT OF RESOLUTION
(SIGN LIMIT
THRESHOLD BAND)
100
0
1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
-20
-15
-10
-5
0
5
10
15
20
-75
-50
-25
INPUT CURRENT [A]
0
25
50
75
100
125
TEMPERATURE [°C]
Figure 2. Differential output voltage (AOP-AON) vs.
input current (IIN).
Figure 3. Quiescent AOP, AON output voltage vs.
temperature.
1.800
620
1.700
IIN = 15A
1.600
VDD = 14V
1.500
580
RSHUNT [mΩ]
OUTPUT VOLTAGE [mV]
600
560
540
VDD = 12V
1.400
1.300
1.200
1.100
520
1.000
VDD = 10V
500
0.900
VDD = 4.8V
0.800
480
-75
-50
-25
0
25
50
TEMPERATURE [°C]
75
100
-75
125
-50
-25
0
25
50
75
100
125
TEMPERATURE [°C]
Figure 4. Differential output voltage (AOP - AON) vs.
VDD and temperature.
Figure 5. Typical shunt resistance vs. temperature.
4
UCC1926
UCC2926
UCC3926
LAB EVALUATION CIRCUIT
The circuit shown uses a pulse generator to switch currents while observing the analog voltage of the sensed
current. A four position switch can be used to experiment
with different gain settings for the programmable amplifier. The OCREF voltage and the NI DC bias voltage can
be adjusted with 1kΩ potentiometers to offset the amplifier output and set the overcurrent comparator threshold.
10kΩ
+10V
13
10µF
0.027µF
4
VS
1k
1
10Ω
PULSE
GENERATOR
TRANSIMPENDANCE
AMPLIFIER rm=3.33mΩ
2
SIGN COMPARATOR
+
–
3
SEL
1.3mΩ
IMAX=20A
6
5
100pF
14
VDD GND
+5V
1k
SW1
10kΩ
SW2
10kΩ
CROSS
SWITCH
15
12
16
10kΩ
1k
PROGRAMMABLE AMPLIFIER
7
0.027µF
+5V
9
8
+
1k
11
–
10
OUT
OVERCURRENT
COMPARATOR
1k
10kΩ
0.027µF
10kΩ
10kΩ
SW3
10kΩ
SW4
100pF
UNITRODE CORPORATION
7 CONTINENTAL BLVD. • MERRIMACK, NH 03054
TEL. (603) 424-2410 • FAX (603) 424-3460
5
UDG-97158
PACKAGE OPTION ADDENDUM
www.ti.com
30-Mar-2005
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
Lead/Ball Finish
MSL Peak Temp (3)
UCC2926DS
OBSOLETE
SOIC
DW
16
TBD
Call TI
Call TI
UCC2926DSTR
OBSOLETE
SOIC
D
16
TBD
Call TI
Call TI
UCC3926DS
OBSOLETE
SOIC
DW
16
TBD
Call TI
Call TI
UCC3926DSTR
OBSOLETE
SOIC
D
16
TBD
Call TI
Call TI
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
Addendum-Page 1
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,
enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
orders and should verify that such information is current and complete. All products are sold subject to TI’s terms
and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
their products and applications using TI components. To minimize the risks associated with customer products
and applications, customers should provide adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,
copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process
in which TI products or services are used. Information published by TI regarding third-party products or services
does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.
Use of such information may require a license from a third party under the patents or other intellectual property
of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without
alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction
of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for
such altered documentation.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that
product or service voids all express and any implied warranties for the associated TI product or service and
is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Following are URLs where you can obtain information on other Texas Instruments products and application
solutions:
Products
Applications
Amplifiers
amplifier.ti.com
Audio
www.ti.com/audio
Data Converters
dataconverter.ti.com
Automotive
www.ti.com/automotive
DSP
dsp.ti.com
Broadband
www.ti.com/broadband
Interface
interface.ti.com
Digital Control
www.ti.com/digitalcontrol
Logic
logic.ti.com
Military
www.ti.com/military
Power Mgmt
power.ti.com
Optical Networking
www.ti.com/opticalnetwork
Microcontrollers
microcontroller.ti.com
Security
www.ti.com/security
Low Power Wireless www.ti.com/lpw
Mailing Address:
Telephony
www.ti.com/telephony
Video & Imaging
www.ti.com/video
Wireless
www.ti.com/wireless
Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright  2006, Texas Instruments Incorporated