ZXCT1023 micropower fixed gain of 50 current monitor ZXCT1023 1 of 6 march 2009 document rev. 1 www.diodes.com ? diodes incorporated a product line o f diodes incorporated ordering information order reference package device marking status reel size (inches) quantity per reel tape w idth (mm) ZXCT1023dfgta tdfn1218 1023 active 7 3000 8 description the ZXCT1023 is a precision high-side current sense monitor. using this type of device eliminates the need to disrupt the ground plane when sensing a load current. the ZXCT1023 has a fixed internal gain of 50 and the only external component required is the external current sense resistor; this combined with its 1.2mm x 1.8mm tdfn package more than quarters the solution size of the zxct1010. the wide input voltage range of 20v down to as low as 2.5v makes it suitable for a range of applications. the combination of operation down to 2.5v and just 3.5a quiescent current makes it ideal for single cell li-ion/polymer battery charge/discharge measurement applications. features ? accurate high-side current sensing ? fixed gain of 50 output scaling ? 2.5v ? 20v operating range ? 3.5a quiescent current ? tdfn1218 package applications ? battery capacity measurement ? battery chargers ? over-current monitor pin connections tdfn1218-4l typical operating circuit s+ s- gnd v out r g r gt r s 1 2 4 3 s+ s- out gnd top view
ZXCT1023 micropower fixed gain of 50 current monitor ZXCT1023 2 of 6 march 2009 document rev. 1 www.diodes.com ? diodes incorporated a product line o f diodes incorporated absolute maximum ratings voltage on s+ 1 .......................................-0.5v to 20v voltage on s- 1,2 , out 1 .................. -0.5v to v s+ +0.5v v sense 3 ............................................... -0.5v to +2.5v junction temperature ............................. -40 to125oc storage temperature ............................. -55 to 150oc package power dissipation (t a = 25oc) tdfn1812-4 ...................................................... mw 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 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, r s . 4. the usable v sense range is limited by the output voltage range; and as such will be reduced at lower v s+ values . 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. esd ratings: human body model .............................. 2000v machine model ........................................ tbd recommended operating conditions parameter min max units v s+ 1 , common-mode sense input range 2.5 20 v v sense , differential sense input voltage range 0 380 4 mv v out ,output volta g e ran g e 0 v s- -1 v t a , ambient temperature range -40 85 c electrical characteristics t a = 25c, v s+ = 3.6v, v sense = 50mv, unless otherwise stated symbol parameter conditions limits unit min. typ. max. v out output voltage v sense = 0mv 0.3 50 mv v sense = 10mv 425 500 575 v sense = 30mv 1.41 1.5 1.59 v v sense = 50mv 2.425 2.5 2.575 v sense = 100mv, v s+ = 20v 4.85 5 5.15 tc 5 output voltage temperature coefficient 50 300 ppm i q ground pin current v sense = 0v 3.5 8 a i s- sense- input current v sense = 0v 100 na acc accuracy v sense = 50mv -3 3 % gain v out /v sense v sense = 50mv 50 v/v r out output resistance 15 k ? bw bandwidth v sense (dc) = 10mv 300 khz v sense (dc) = 50mv 1 mhz psrr 6 power supply rejection ratio v sense = 30mv, v s+ = 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, v s+ .
ZXCT1023 micropower fixed gain of 50 current monitor ZXCT1023 3 of 6 march 2009 document rev. 1 www.diodes.com ? diodes incorporated a product line o f diodes incorporated typical dc characteristics v sense = 0v, v s+ = 3.6v 0 0.5 1 1.5 2 2.5 2 4 6 8 10 12 14 16 18 20 v s+ (v) i s+ (a) t a = -40c t a = 0c t a = 85c vs+ = 3.6v relative to gain = 50 -2% -1% 0% 1% 2% 3% 0 1020304050 v sense (mv) differential gain error t a = 85c t a = -40c t a = 0c t a = 25c s+ input current vs supply voltage normalised gain error vs sense voltage v s+ = 3.6v -40c 25c 85c 20 30 40 50 60 70 0246810 v sense (mv) differential gain ( v out / v sense ) t a = 0c v s+ = 3.6v 0 0.5 1 1.5 2 2.5 3 3.5 0 102030405060 v sense (mv) v out (v) t a = 85c t a = 25c t a = 0c t a = -40c differential gain vs sense voltage output voltage vs sense voltage t a = 25c v sense = 10mv v sense = 30mv v sense = 50mv 0 0.5 1 1.5 2 2.5 3 2 4 6 8 10 12 14 16 18 20 v s+ (v) v out (v) v s+ =3.6v w.r.t. v out at 25c v sense = 10mv, 30mv, 50mv 10mv 30mv 30mv 50mv 50mv -0.6% -0.4% -0.2% 0.0% 0.2% 0.4% 0.6% -40 -15 10 35 60 85 temperature (c) v out %error output voltage v s+ input voltage relative output voltage change vs temperature
ZXCT1023 micropower fixed gain of 50 current monitor ZXCT1023 4 of 6 march 2009 document rev. 1 www.diodes.com ? diodes incorporated a product line o f diodes incorporated typical ac characteristics -20 -10 0 10 20 30 40 10e+0 100e+0 1e+3 10e+3 100e+3 1e+6 10e+6 frequency (hz) gain (db) v sense = 50mv v sense = 10mv v s+ =3.6v t a =25c t a = 25c v sense = 50mv 0 10 20 30 40 50 60 70 0.01 0.1 1 10 100 1000 frequency (khz) psrr (db) v s+ = 10v v s+ = small signal frequency response power supply rejection ratio -5 0 5 10 15 20 25 0 50 100 150 200 250 300 time (s) input (mv) -0.2 0 0.2 0.4 0.6 0.8 1 1.2 output (v) input output v s+ =3.6v, t a = 25c v sense = 20mv -10 0 10 20 30 40 50 60 0 50 100 150 200 time (s) input (mv) -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 output (v) input output v s+ =3.6v, t a = 25c v sense = 50mv l large signal pulse response 20mv large signal pulse response 50mv 49 50 51 52 53 54 55 56 0 50 100 150 200 time (s) sense voltage (mv) 2.45 2.50 2.55 2.60 2.65 2.70 2.75 2.80 output voltage (v) input output v s+ =3.6v, t a =25c v sense = 50mv(dc) + 5mv 44 45 46 47 48 49 50 51 0 25 50 75 100 125 150 time (s) v sense (mv) 2.20 2.25 2.30 2.35 2.40 2.45 2.50 2.55 v out (v) input output v s+ =3.6v, t a =25c v sense = 50mv(dc) - 5mv pulse small signal positive pulse response small signal negative pulse response pin out information package name pin function 1 out voltage output. the output voltage is referenced to gnd. the overall voltage gain of v out = 50 x v sense where v sense = v s+ - v s- 2 gnd ground and substrate connection of device. nc no connection 3 s- high impedance negative sense voltage input 4 s+ positive sense input. also acts as power supply pin to ZXCT1023
ZXCT1023 micropower fixed gain of 50 current monitor ZXCT1023 5 of 6 march 2009 document rev. 1 www.diodes.com ? diodes incorporated a product line o f 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. the ZXCT1023 has its gain setting resistor, r g , set at 15k ? which further reduces power consumption at larger v sense . application examples please refer to zetex an39 for sample applications. package outline tdfn1812-4 package s+ s- gnd v ou t r g r gt r s
ZXCT1023 micropower fixed gain of 50 current monitor ZXCT1023 6 of 6 march 2009 document rev. 1 www.diodes.com ? diodes incorporated a product line o f diodes incorporated important notice diodes incorporated makes no warranty of any kind, express or implied, with regarding 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 liabi lity 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 a pplication. 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 expect ed 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 ? 2009, diodes incorporated www.diodes.com
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