A Product Line of Diodes Incorporated ZXCT1023 MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR Description Pin Connections 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 * * * * * TDFN1218-4L OUT 1 4 S+ GND 2 3 STop View Typical Operating Circuit Accurate high-side current sensing Fixed gain of 50 output scaling RS S+ 2.5V - 20V operating range 3.5A quiescent current S- RGT TDFN1218 package Applications * * * Battery capacity measurement VOUT Battery chargers RG Over-current monitor GND Ordering Information Order Reference Package ZXCT1023DFGTA TDFN1218 ZXCT1023 Document Rev. 1 Device Marking 1023 Status Active 1 of 6 www.diodes.com Reel Size (inches) 7 Quantity per Reel 3000 Tape Width (mm) 8 MARCH 2009 (c)Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1023 MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR Absolute maximum ratings Voltage on S+1 .......................................-0.5V to 20V Voltage on S-1,2, OUT1 .................. -0.5V to VS++0.5V VSENSE3 ............................................... -0.5V to +2.5V Junction temperature ............................. -40 to125C Storage temperature ............................. -55 to 150C Package power dissipation (TA = 25C) 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 VSENSE not being exceeded. 3. VSENSE is defined as the voltage difference across the sense resistor, RS. 4. The usable VSENSE range is limited by the output voltage range; and as such will be reduced at lower VS+ 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 Common-mode sense input range VSENSE, Differential Sense Input voltage range VOUT, Output Voltage range TA, Ambient temperature range VS+1, MIN MAX Units 2.5 20 V 0 3804 mV 0 VS- - 1 V -40 85 C Electrical characteristics TA = 25C, VS+ = 3.6V, VSENSE = 50mV, unless otherwise stated Symbol Parameter VOUT Output voltage Conditions VSENSE = 0mV VSENSE = 10mV VSENSE = 30mV VSENSE = 50mV VSENSE = 100mV, VS+ = 20V IQ ISAcc Gain ROUT Output voltage temperature coefficient Ground pin current SENSE- input current Accuracy VOUT/VSENSE Output resistance BW Bandwidth VSENSE (DC) = 10mV VSENSE (DC) = 50mV Power supply rejection ratio VSENSE = 30mV, VS+ = 2.5 to 20V TC5 PSRR6 VSENSE = 0V VSENSE = 0V VSENSE = 50mV VSENSE = 50mV Limits Typ. Max. 0.3 50 425 500 575 1.41 1.5 1.59 2.425 2.5 2.575 4.85 5 5.15 Min. mV V 50 300 ppm 3.5 8 100 3 50 15 300 1 A nA % V/V k kHz MHz 60 dB -3 50 Unit Notes 5. TC limits are determined by characterization. 6. PSRR is defined as change in output voltage per change in S+ voltage, VS+. ZXCT1023 Document Rev. 1 2 of 6 www.diodes.com MARCH 2009 (c)Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1023 MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR Typical DC characteristics 2.5 3% TA = 85C VSENSE = 0V, VS+ = 3.6V TA = -40C Differential Gain Error 2 IS+ (A) TA = 0C 1.5 TA = 85C 1 Vs+ = 3.6v Relative to gain = 50 2% TA = -40C 1% TA = 25C 0% TA = 0C -1% 0.5 -2% 0 2 4 6 8 10 12 14 VS+ (V) 16 18 0 20 S+ input current vs Supply voltage TA = 25C 2.5 85C TA = 0C 2 TA = -40C 1.5 40 1 30 0.5 20 0 0 2 4 VSENSE (mV) 6 8 10 0 10 Differential gain Vs Sense voltage 20 30 VSENSE (mV) 40 50 60 Output Voltage Vs Sense voltage 0.6% 3 TA = 25C VSENSE = 50mV 2.5 0.4% 2 VS+ =3.6V w.r.t. VOUT at 25C VSENSE = 10mV, 30mV, 50mV 10mV 0.2% VSENSE = 30mV 1.5 1 VOUT %Error VOUT (V) 50 TA = 85C VS+ = 3.6V 3 25C 50 40 Normalised gain error Vs Sense voltage VS+ = 3.6V -40C 60 20 30 VSENSE (mV) 3.5 TA = 0C VOUT (V) Differential Gain (VOUT/VSENSE) 70 10 30mV 0.0% 50mV 50mV 30mV -0.2% VSENSE = 10mV 0.5 -0.4% 0 2 4 6 8 10 12 14 16 VS+ (V) Output voltage VS+ Input voltage ZXCT1023 Document Rev. 1 18 20 -0.6% -40 -15 10 35 Temperature (C) 60 85 Relative output voltage change Vs Temperature 3 of 6 www.diodes.com MARCH 2009 (c)Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1023 MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR Typical AC characteristics 40 70 VSENSE = 50mV 30 VS+=3.6V TA =25C 50 PSRR (dB) 20 VSENSE = 10mV 10 0 40 VS+ = 10V 30 VS+ = 20 -10 10 100E+0 1E+3 10E+3 100E+3 frequency (Hz) 1E+6 10E+6 0 0.01 1.2 60 1 50 0.8 40 0.1 Input (mV) 15 Input 0.6 Output 0.4 5 0.2 0 0 50 100 150 -5 200 0 300 250 Input (mV) 20 10 20 53 10 0.5 0 0.0 0 50 100 Time (s) -0.5 200 150 52 51 2.75 50 2.50 2.70 49 2.45 2.60 2.55 Output 50 49 150 VS+=3.6V, TA =25C VSENSE = 50mV(DC) - 5mV pulse 2.80 2.65 100 time (s) 1.0 Output VSENSE (mV) Input 50 1.5 Input -10 Output voltage (V) Sense voltage (mV) 55 0 2.5 Large signal pulse response 50mV VS+=3.6V, TA =25C VSENSE = 50mV(DC) + 5mV 51 3.0 2.0 30 -0.2 Time (s) 54 1000 VS+=3.6V, TA = 25C VSENSE = 50mV l Large signal pulse response 20mV 56 100 Power supply rejection ratio VS+=3.6V, TA = 25C VSENSE = 20mV Output (V) Small signal frequency response 25 1 10 Frequency (kHz) 48 2.55 2.40 Input 47 2.35 46 2.50 45 2.45 200 44 Output 2.30 2.25 0 Small signal positive pulse response 25 50 75 time (s) 100 125 2.20 150 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 VOUT = 50 x VSENSE where VSENSE = VS+ - VS- 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 Document Rev. 1 Output (V) -20 10E+0 4 of 6 www.diodes.com MARCH 2009 (c)Diodes Incorporated VOUT (V) Gain (dB) TA = 25C VSENSE = 50mV 60 A Product Line of Diodes Incorporated ZXCT1023 MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR 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. S- S+ RS RGT VOUT RG GND The ZXCT1023 has its gain setting resistor, RG, set at 15k which further reduces power consumption at larger VSENSE. Application Examples Please refer to Zetex AN39 for sample applications. Package Outline TDFN1812-4 package ZXCT1023 Document Rev. 1 5 of 6 www.diodes.com MARCH 2009 (c)Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1023 MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR 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). 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Life support devices or systems are devices or systems which: 1. are intended to implant into the body, or the 2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in 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. 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