ZXCT1023

Document overview

  • Manufacturer or author: Diodes Incorporated
  • PDF pages: 8

Technical content

Features

  • Accurate high-side current sensing
  • Fixed gain of 50 output scaling
  • 2.5V – 20V operating range
  • 3.5µA quiescent current
  • TDFN1218 package Pin Assignments 1 4 2 S- OUT GND TDFN1218-4L Top View

Applications

  • Battery capacity measurement
  • Battery chargers
  • Over-current monitor Typical Application Circuit GND S-RS RGT VOUT RG

MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR ZXCT1023 Document number: DS31997 Rev. 3 - 2 2 of 8 www.diodes.com June 2011 © Diodes Incorporated Pin Descriptions Pin Name Pin Number Description

1 OUT

Voltage output. The output voltage is referenced to GND. The overall voltage gain is 50, i.e., VOUT = 50 x VSENSE where VSENSE = VS+ - VS-

2 GND Ground and substrate connection of device

3 S- High impedence negative sense voltage input

4 S+ Positive sense input. Also acts as power supply pin to ZXCT1023 Central Paddle Substrate. Connect to GND Absolute Maximum Ratings Description Rating Unit Voltage on S+ (Note 1) -0.5 to 20 V Voltage on S- (Note 1, 2), OUT(Note 1) -0.5 VS++0.5 V VSENSE (Note 3) -0.5 to +2.5 V Junction Temperature -40 to 125 °C Storage Temperature -55 to 150 °C Package Power Dissipation (TA = 25°C) TDFN1218 mW ESD Ratings Human Body Model 2000 V Machine Model 150 V These are stress ratings only. Operation outside the absolute maximum ratings may cause device failure. Operation at the absolute maximum rating for extended periods may reduce device reliability. Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when handling and transporting these devices. Notes: 1. Measured with respect to GND pin 2. Subject to absolute maximum V SENSE not being exceeded. 3. V SENSE is defined as the voltage difference across the sense resistor, RS. 4. The usable V SENSE range is limited by the output voltage range; and as such will be reduced at lower VS+ values. Recommended Operating Conditions (TA = 25°C) Symbol Parameter Min Max Unit VS+ (Note 1) Common-Mode Sense Input Range 2.5 20 V VSENSE Differential Sense Input Voltage Range 0 380 (Note 4) mV VOUT Output Voltage Range 0 VS- - 1 V TA Ambient Temperature Range -40 85 °C

MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR ZXCT1023 Document number: DS31997 Rev. 3 - 2 3 of 8 www.diodes.com June 2011 © Diodes Incorporated Electrical Characteristics (TA = 25°C, VS+ = 3.6V, VSENSE = 50mV, unless otherwise stated) Symbol Parameter Conditions Limits Unit Min. Typ. Max. VOUT Output voltage VSENSE = 0mV 0.3 50 mV VSENSE = 10mV 425 500 575 VSENSE = 30mV 1.41 1.5 1.59 V VSENSE = 50mV 2.425 2.5 2.575 VSENSE = 100mV, VS+ = 20V 4.85 5 5.15 TC (Note 5) Output voltage temperature coefficient 50 300 ppm/°C IQ Ground pin current VSENSE = 0V 3.5 8 μA IS- SENSE- input current VSENSE = 0V 100 nA Acc Accuracy VSENSE = 50mV -3 3 % Gain VOUT/VSENSE V SENSE = 50mV 50 V/V ROUT Output resistance 15 kΩ BW Bandwidth VSENSE (DC) = 10mV 300 kHz VSENSE (DC) = 50mV 1 MHz PSRR (Note 6) Power supply rejection ratio VSENSE = 30mV, VS+ = 2.5 to 20V 50 60 dB Notes 5. TC limits are determined by characterization. 6. PSRR is defined as change in output voltage per change in S+ voltage, VS+.

MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR ZXCT1023 Document number: DS31997 Rev. 3 - 2 4 of 8 www.diodes.com June 2011 © Diodes Incorporated Typical DC Characteristics VSENSE = 0V, VS+ = 3.6V 0.5 1.5 2.5 2 4 6 8 10 12 14 16 18 20 VS+ (V) IS+ (µA) TA = -40°C TA = 0°C TA = 85°C Vs+ = 3.6v Relative to gain = 50 -2% -1% 0 1 02 03 04 05 0 V SENSE (mV) Differential Gain Error TA = 85°C TA = -40°C TA = 0°C TA = 25°C S+ Input Current vs. Supply voltage Normalised Gain Error vs. Sense Voltage VS+ = 3.6V -40°C 25°C 85°C 02468 1 0 VSENSE (mV) Differential Gain (ΔVOUT/ΔVSENSE) TA = 0°C VS+ = 3.6V 0.5 1.5 2.5 3.5 0 1 02 03 04 05 06 0 VSENSE (mV) VOUT (V) TA = 85°C TA = 25°C TA = 0°C TA = -40°C Differential Gain vs. Sense Voltage Output Voltage vs. Sense Voltage TA = 25°C VSENSE = 10mV VSENSE = 30mV VSENSE = 50mV 0.5 1.5 2.5 2 4 6 8 10 12 14 16 18 20 VS+ (V) VOUT (V) VS+ =3.6V w.r.t. VOUT at 25°C VSENSE = 10mV, 30mV, 50mV10mV 30mV 30mV50mV 50mV -0.6% -0.4% -0.2% 0.0% 0.2% 0.4% 0.6% -40 -15 10 35 60 85 Temperature (°C) ΔVOUT %Error Output Voltage vs. Input voltage Relative Output Voltage Change vs. Temperature

MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR ZXCT1023 Document number: DS31997 Rev. 3 - 2 5 of 8 www.diodes.com June 2011 © Diodes Incorporated Typical AC Characteristics -20 -10 10E+0 100E+0 1E+3 10E+3 100E+3 1E+6 10E frequency (Hz) Gain (dB) VSENSE = 50mV VSENSE = 10mV VS+=3.6V TA =25°C TA = 25°C VSENSE = 50mV 0.01 0.1 1 10 100 100 Frequency (kHz) PSRR (dB) VS+ = 10V VS+ = Small Signal Frequency Response Power Supply Rejection Ratio 0 50 100 150 200 250 300 Time (µs) Input (mV) -0.2 0.2 0.4 0.6 0.8 1.2 Output (V) Input Output VS+=3.6V, TA = 25°C VSENSE = 20mV -10 0 50 100 150 200 Time (µs) Input (mV) -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Output (V) Input Output VS+=3.6V, TA = 25°C VSENSE = 50mV Large Signal Pulse Response 20mV Large Signal Pulse Response 50mV 0 50 100 150 200 time (µs) Sense voltage (mV) 2.45 2.50 2.55 2.60 2.65 2.70 2.75 2.80 Output voltage (V) Input Output VS+=3.6V, TA =25°C VSENSE = 50mV(DC) + 5mV 0 25 50 75 100 125 150 time (µs) VSENSE (mV) 2.20 2.25 2.30 2.35 2.40 2.45 2.50 2.55 VOUT (V)Input Output VS+=3.6V, TA =25°C VSENSE = 50mV(DC) - 5mV pulse Small Signal Positive Pulse Response Small Signal Negative Pulse Response

MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR ZXCT1023 Document number: DS31997 Rev. 3 - 2 6 of 8 www.diodes.com June 2011 © Diodes Incorporated

Application Information

The ZXCT1023 is line powered (derives its power from the rail being sensed) this reduces the number of pins used and PCB trace routing. The fixed gain of 50 reduces the PCB area by reducing the number of external components. The only external component required is the sense resistor. This coupled with the 1.2mm x 1.8mm TDFN package makes the solution size very small. The fixed gain of 50 has been chosen to meet the normal requirements of most applications. GND S-RS RGT VOUT RG The ZXCT1023 has its gain setting resistor, R G, set at 15kΩ which further reduces power consumption at larger VSENSE. Application Examples Please refer to Zetex AN39 for sample applications.

Ordering Information

Order Reference Package Device Marking Status Reel Size (inches) Quantity Per Reel Tape Width (mm) ZXCT1023DFGTA TDFN1218 23 Active 7 3000 8

MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR ZXCT1023 Document number: DS31997 Rev. 3 - 2 7 of 8 www.diodes.com June 2011 © Diodes Incorporated Package Outline Dimensions (All Dimensions in mm) TDFN1218-4 Recommended PCB Land Pattern

MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR ZXCT1023 Document number: DS31997 Rev. 3 - 2 8 of 8 www.diodes.com June 2011 © Diodes Incorporated IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or ot her changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or trademark rights, nor the rights of others. Any Customer or user of this document or products desc ribed herein in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated website, harmless against all damages. Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthoriz ed sales channel. Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fee s arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized application. Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings noted herein may also be covered by one or more United States, international or foreign trademarks. LIFE SUPPORT Diodes Incorporated 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 Diodes Incorporated. 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 properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. B. A critical component is any component in a life support device 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. Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support dev ices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems. Copyright © 2011, Diodes Incorporated www.diodes.com