ZXCT1051_0611 ZETEX | Alldatasheet
Document overview
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Technical content
Features
- Accurate down to end current sensing Output voltage scaling x10 0 t o V CC-2V sense input range 2.7 to 20V supply range 50 µA quiescent current 1% typical accuracy SOT23-5 package Pin connections The ZXCT1051 provides a fixed gain of 10 thereby removing the need for an additional resistor.Applications Power supply DC motor and solenoid control Battery management Over current monitor Power management Short circuit detection Typical application circuit
Ordering information
Order code Package Partmark Reel size (inches) Tape width (mm) Quantity per reel ZXCT1051E5TA SOT23-5 1051 7 8 3,000
Issue 2 - November 2006 2 www.zetex.com © Zetex Semiconductors plc 2006 Absolute maximum ratings VCC max. 20V Voltage on VSENSE- and VSENSE+ -0.6 to V CC Voltage on all other pins -0.6V and V CC +0.6V VSENSE "(VSENSE+) - (VSENSE-) 500mV Operating temperature, Tamb -40 to 125°C Storage temperature -55 to 150°C Maximum junction temperature 150°C Package power dissipation 300mW at T amb = 25°C (de-rate to zero at 150°C) Operation above the absolute maximum rating may cause device failure. Operation at the absolute maximum ratings, for extended periods, may reduce device reliability. Recommended operating conditions Pin function table Parameter Min. Max. Units VSENSE+ Common-mode sense input range 0 V CC-2 V VCC Supply voltage range 2.7 20 V VSENSE Differential sense input voltage range 0 0.3 V VOUT Output voltage range 0 V CC - 2 V Tamb Ambient temperature range -40 125 °C Pin Name Description 1V CC This is the analog supply and provides power to internal circuitry
2 GND Ground pin
3 OUT Output voltage pin. 4V SENSE+ This is the positive input of the current monitor and has an input range from 0V up to VCC – 2V. 5V SENSE- This is the negative input of the current monitor and has an input range from 0V up to VCC – 2V. The current through this pin varies with differential sense voltage.
Issue 2 - November 2006 3 www.zetex.com © Zetex Semiconductors plc 2006
Electrical characteristics
Test conditions Tamb = 25°C, VSENSE+ = 10V, VCC = 12V, VSENSE = 100mV NOTES: (a) VSENSE = "VSENSE+" - "VSENSE-" (b) Temperature dependent measurements are extracted from characterization and simulation results. Symbol Parameter Conditions Min. Typ. Max. Units IQ VCC pin current V SENSE = 0V 45 70 µA VOUT Output voltage V SENSE = 0V =30mV =100mV =150mV 291 0.98 1.45 300 1.00 1.50 309 1.02 1.55 mV mV V V I SENSE+V SENSE+ input current V SENSE = 0V 10 150 nA ISENSE-V SENSE- input current V SENSE = 0V 60 150 nA VOUT TC V OUT variation with temperature See note (b) 300 ppm/°C ROUT Output resistance 2.5 3.75 5 k/H9024 Gain V OUT/VSENSE 10 Accuracy Total output error -2 2 % BW Bandwidth V SENSE(DC) = 10mV VSENSE(AC) = 10mVPP CL = 5pF, 300 kHz VSENSE(DC) = 100mV 1M H z PSRR Power supply rejection ratio refered to output V CC = 2.7V to 20V VSENSE- = 0V 58 dB CMRR Common mode rejection ratio refered to output V CC = 20V VSENSE+ = 0 to 18V 66 dB
Issue 2 - November 2006 4 www.zetex.com © Zetex Semiconductors plc 2006 Typical characteristics Supply Current v Input Voltage ICC Supply Current (A) Supply Current v Supply Voltage ICC Supply Current (A) Sense- Current v Supply Voltage IS- Sense Current (A) Sense- Current v Temperature Percentage Change IS- (%) Supply Current v Sense Voltage ICC Supply Current (A) Sense- Current v Sense Voltage IS- Sense Current (A)
Issue 2 - November 2006 5 www.zetex.com © Zetex Semiconductors plc 2006 Typical characteristics 1E-3 0.01 0.1 10m 100m -20 -15 -10 -5 0 5 10 15 20 900 950 1000 1050 1100 0 50m 100m 150m 9.9 10.0 10.1 0 2 4 6 8 1 01 21 41 61 82 0 0 5 10 15 20 -12 -40 -20 0 20 40 60 80 100 120 VOUT - Output Voltage (V) VOUT v Load Current VOUT - Output Voltage (mV) µ Incremental Gain v Sense Voltage Incremental Gain Common Mode Characteristic ∆VOUT - Output Voltage (mV) Supply Characteristic ∆VOUT - Output Voltage (mV) Temperature Characteristic ∆VOUT Output Voltage (mV)
Issue 2 - November 2006 6 www.zetex.com © Zetex Semiconductors plc 2006 Typical characteristics 100 1k 10k 100k 1M 10M -60 -50 -40 -30 -20 -10 02468 1 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 02468 1 0 0.88 0.90 0.92 0.94 0.96 0.98 1.00 1.02 1000 10000 100000 1000000 1E7 100 1k 10k 100k 1M 0 5 10 15 20 25 30 35 40 Bandwidth Gain (dB) Large Signal Pulse Response VOUT - Output Voltage (V) µ Small Signal Pulse Response VOUT - Output Voltage (V) µ PSRR Supply Rejection (dB) CMRR Common Mode Rejection (dB) Turn on/off Characteristic µ VOUT - Output Voltage (V)
Issue 2 - November 2006 7 www.zetex.com © Zetex Semiconductors plc 2006
Application information
The ZXCT1051 is Zetex’ first current monitor with a separate power supply pin. All biasing for the internal amplifiers comes from its separate V CC input and is not ‘line powered’, unlike the ZXCT1021. This means that at very small sense voltages the ZXCT1051 draws very little current (<1µA) from the lines being sensed. The separate V CC pin enables the ZXCT1051 to be operated at sense line voltages down to 0V, where the ZXCT1021 would switch off. This feature enables the ZXCT1051 to be used to sense the currents flowing through lines that have been shorted to ground and is Zetex’ first current monitor to do this. Basic operation Load current from V IN is drawn through R SENSE developing a voltage V SENSE across the ZXCT1051. The internal amplifier forces V SENSE across internal resistance R SH causing a current to flow through transistor Q1. This current is then converted to a voltage by R G. A ratio of 10:1 between RSH and R G creates the fixed gain of 10 with an output impedance equal to R G (see electrical characteristics for output current-voltage characteristics). The gain equation of the ZXCT1051 is: The maximum differential input voltage, VSENSE, is 150mV (IL * RSENSE); however voltages up to 500mV will not damage it. This can be increased further by the inclusion of a resistor, R LIM, between VSENSE- pin and the load. For best performance RSENSE should be connected as close to the VSENSE+ and VSENSE- pins thus minimizing any series resistance with RSENSE. RSENSE VSENSE+ VSENSE- VOUT VCC VRAIL RG RSHQ1 GND GND Load VSENSE ILRSENSE RG RSH
Issue 2 - November 2006 8 www.zetex.com © Zetex Semiconductors plc 2006 The ZXCT1051 has been designed to allow it to operate from supplies (VCC) ranging from 2.7V to 20V while sensing common mode signals from 0V up to VCC -2V. When choosing appropriate values for R SENSE a compromise must be reached between in-line signal loss (including potential power dissipation effects) and small signal accuracy. Higher values for RSENSE gives better accuracy at low load currents by reducing the inaccuracies due to internal offsets. For best operation the ZXCT1051 has been designed to operate with V SENSE of the order of 50mV to 150mV. Due to the very nature of current monitors they tend to saturate at very low sense voltages. This is due to them being operated from single supply and that the basic configuration is that of a unipolar voltage to current to voltage converter. The internal amplifiers at the heart of the current monitor may well have a bipolar offset voltage but the output cannot go negative. For this reason the ZXCT1051 has been designed to operate in a linear manner over a V SENSE range of 10mV to 150mV range, however it will still be monotonic down to VSENSE of 0V. The device has a fixed DC voltage gain of 10; no external scaling resist ors are required for the output. Output voltage is simply defined as: VOUT = gain x VSENSE (V)
Issue 2 - November 2006 9 www.zetex.com © Zetex Semiconductors plc 2006 Packaging details - SOT23-5 Note: Controlling dimensions are in millimeters. Approximate dimensions are provided in inches DIM Millimeters Inches Min. Max. Min. Max. A 0.90 1.45 0.0354 0.0570 A1 0.00 0.15 0.00 0.0059 A2 0.90 1.30 0.0354 0.0511 b 0.20 0.50 0.0078 0.0196 C 0.09 0.26 0.0035 0.0102 D 2.70 3.10 0.1062 0.1220 E 2.20 3.20 0.0866 0.1181 E1 1.30 1.80 0.0511 0.0708 e 0.95 REF 0.0374 REF e1 1.90 REF 0.0748 REF L 0.10 0.60 0.0039 0.0236 a° 0° 30° 0° 30°
Issue 2 - November 2006 10 www.zetex.com © Zetex Semiconductors plc 2006 Definitions Product change Zetex Semiconductors reserves the right to alter, without notice, specifications, design, price or conditions of supply of any product or service. Customers are solely responsible for obtaining the latest relevant information before placing orders. Applications disclaimer The circuits in this design/application note are offered as desi gn ideas. It is the responsibility of the user to ensure that t he circuit is fit for the user’s application and meets with the user’s requirements. No representation or warranty is given and no liability whatsoev er is assumed by Zetex with respect to the accuracy or use of such in formation, or infringement of patents or other intellectual prop erty rights arising from such use or otherwise. Zetex does not assume any le gal responsibility or will not be held legally liable (whether in contract, tort (including negligence), breach of statutory duty, restricti on or otherwise) for any damages, loss of profit, business, con tract, opportunity or consequential loss in the use of these circuit applications, under any circumstances. Life support Zetex products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Zetex Semiconductors plc. As used herein: A. Life support devices or systems are devices or systems which: 1. are intended to implant into the body or 2. support or sustain life and whose failure to perform when proper ly used in accordance with instructions for use provided in the labelling can be reasonably expected to result in significant injury to the user. B. A critical component is any component in a life support devi ce or system whose failure to perform can be reasonably expected to cause the failure of the life support device or to affect its safety or effectiveness. Reproduction The product specifications contained in this publication are issu ed to provide outline information only which (unless agreed by the company in writing) may not be used, applied or reproduced for any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. Terms and Conditions All products are sold subjects to Zetex’ terms and conditions of sale, and this disclaimer (save in the event of a conflict bet ween the two when the terms of the contract shall prevail) according to region, supplied at the time of order acknowledgement. For the latest information on technology, delivery terms and conditions and prices, please contact your nearest Zetex sales office or visit: www.zetex.com Quality of product Zetex is an ISO 9001 and TS16949 certified semiconductor manufacturer. To ensure quality of service and products we strongly advise the purchase of parts dire ctly from Zetex Semiconductors or one of our regionally authorized distributors. For a complete listing of authorized distributors please visit: www.zetex.com/salesnetwork Zetex Semiconductors does not warrant or accept any liability whatsoever in respect of any parts purchased through unauthorized sales channels. ESD (Electrostatic discharge) Semiconductor devices are susceptible to damage by ESD. Suitable precautions should be taken when handling and transporting devices. The possible damage to devices depends on the circumstances of the handling and transporting, and the nature of the device. The extent of damage can vary from immediate functional or parametric malfunc tion to degradation of function or performance in use over ti me. Devices suspected of being affected should be replaced. Green compliance Zetex Semiconductors is committed to envir onmental excellence in all aspects of its operations which includes meeting or exce eding regulatory requirements with respect to the use of hazardous s ubstances. Numerous successful programs have been implemented to reduce the use of hazardous substances and/or emissions. All Zetex components are compliant with the Ro HS directive, and through this it is supporting its customers in their compliance with WEEE and ELV directives. Product status key: “Preview” Future device intended for production at some point. Samples may be available “Active” Product status recommended for new designs “Last time buy (LTB)” Device will be discontinued and last time buy period and delivery is in effect “Not recommended for new designs” Device is still in production to support existing designs and production “Obsolete” Production ha s been discontinued Datasheet status key: “Draft version” This term denotes a very early datasheet ver sion and contains highly provisional information, which may change in any manner without notice. “Provisional version” This term denotes a pre-release datasheet. It provides a clear indication of anticipated performance. However, changes to the test conditions and specifications may occur, at any time and without notice. “Issue” This term denotes an issued datasheet cont aining finalized specifications. However, changes to specifications may occur, at any time and without notice. Zetex sales offices Europe Zetex GmbH Kustermann-park Balanstraße 59 D-81541 München Germany Telefon: (49) 89 45 49 49 0 Fax: (49) 89 45 49 49 49 europe.sales@zetex.com Americas Zetex Inc
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