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 3.5µA 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 2.5V – 20V operating range 3.5µA quiescent current TDFN1218 package S+ RS S- RGT – + Applications • Battery capacity measurement • Battery chargers • Over-current monitor VOUT RG GND Ordering Information Order Reference Package Device Marking Status Reel Size (inches) Quantity per Reel Tape Width (mm) ZXCT1023DFGTA TDFN1218 1023 Active 7 3000 8 ZXCT1023 Rev. 2 1 of 7 www.diodes.com October 2009 © Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1023 MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR Absolute maximum ratings 1 Voltage on S+ ................................................. -0.5V to 20V 1,2 1 Voltage on S- , OUT ............................ -0.5V to VS++0.5V 3 VSENSE ........................................................... -0.5V to +2.5V Junction temperature ........................................ -40 to125ºC Storage temperature ........................................ -55 to 150ºC Package power dissipation (TA = 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 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 MIN 1 VS+ , Common-mode sense 2.5 input range VSENSE, Differential Sense Input 0 voltage range VOUT, Output Voltage range 0 TA, Ambient temperature -40 range MAX Units 20 V 380 4 mV VS- - 1 V 85 °C Electrical characteristics TA = 25°C, VS+ = 3.6V, VSENSE = 50mV, unless otherwise stated Symbol VOUT TC 5 IQ ISAcc Gain ROUT BW PSRR6 Notes 5. 6. Parameter Output voltage Output voltage temperature coefficient Ground pin current SENSE- input current Accuracy VOUT/VSENSE Output resistance VSENSE = 0mV VSENSE = 10mV VSENSE = 30mV VSENSE = 50mV VSENSE = 100mV, VS+ = 20V VSENSE = 0V VSENSE = 0V VSENSE = 50mV VSENSE = 50mV VSENSE (DC) = 10mV VSENSE (DC) = 50mV Power supply rejection ratio VSENSE = 30mV, VS+ = 2.5 to 20V Limits Typ. 0.3 425 500 1.41 1.5 2.425 2.5 4.85 5 Min. 50 Max. 50 575 1.59 2.575 5.15 Unit mV V 50 300 ppm 3.5 8 100 3 μA nA % V/V kΩ kHz MHz dB -3 Bandwidth 50 15 300 1 60 TC limits are determined by characterization. PSRR is defined as change in output voltage per change in S+ voltage, VS+. ZXCT1023 Rev. 2 Conditions 2 of 7 www.diodes.com October 2009 © Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1023 MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR Typical DC characteristics 2.5 3% TA = 85°C VSENSE = 0V, VS+ = 3.6V Vs+ = 3.6v Relative to gain = 50 TA = -40°C Differential Gain Error 2 IS+ (µA) TA = 0°C 1.5 TA = 85°C 1 2% TA = -40°C 1% TA = 25°C 0% TA = 0°C -1% 0.5 -2% 0 0 2 4 6 8 10 12 14 16 18 10 20 30 VSENSE (mV) 20 VS+ (V) S+ input current vs Supply voltage VS+ = 3.6V 3 TA = 25°C 60 25°C 2.5 85°C TA = 0°C 2 TA = -40°C 1.5 40 1 30 0.5 20 0 0 2 4 6 8 10 0 10 20 VSENSE (mV) Differential gain Vs Sense voltage 30 VSENSE (mV) 40 50 60 Output Voltage Vs Sense voltage 0.6% 3 TA = 25°C VSENSE = 50mV 2.5 VS+ =3.6V w.r.t. VOUT at 25°C VSENSE = 10mV, 30mV, 50mV 0.4% 10mV 2 0.2% VSENSE = 30mV 1.5 1 ΔVOUT %Error VOUT (V) TA = 85°C VS+ = 3.6V -40°C 50 50 Normalised gain error Vs Sense voltage 3.5 TA = 0°C VOUT (V) Differential Gain (ΔVOUT/ΔVSENSE) 70 40 30mV 0.0% 50mV 50mV 30mV -0.2% VSENSE = 10mV 0.5 -0.4% 0 2 4 6 8 10 12 14 16 18 20 -0.6% -40 VS+ (V) Output voltage VS+ Input voltage ZXCT1023 Rev. 2 -15 10 35 Temperature (°C) 60 85 Relative output voltage change Vs Temperature 3 of 7 www.diodes.com October 2009 © Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1023 MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR Typical AC characteristics 70 40 VSENSE = 50mV 30 VS+=3.6V TA =25°C 50 PSRR (dB) 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 20 Input (mV) 15 Input 10 0.6 Output 0.4 5 1000 VS+=3.6V, TA = 25°C VSENSE = 50mV l 3.0 2.5 2.0 30 1.5 Input 20 1.0 Output 10 0.5 0 0.0 0.2 0 0 50 100 -5 150 200 250 0 300 -10 0 -0.2 Time (µs) Large signal pulse response 20mV 54 Input 53 Output 50 2.50 2.70 49 2.45 2.55 45 2.45 200 44 150 2.35 46 2.50 100 time (µs) 2.40 Input 47 49 50 2.55 48 50 0 VS+=3.6V, TA =25°C VSENSE = 50mV(DC) - 5mV pulse 2.75 2.60 51 -0.5 200 150 Large signal pulse response 50mV 2.65 52 100 Time (µs) 51 VSENSE (mV) 55 50 2.80 Output voltage (V) VS+=3.6V, TA =25°C VSENSE = 50mV(DC) + 5mV l 56 Sense voltage (mV) 100 Power supply rejection ratio Input (mV) VS+=3.6V, TA = 25°C VSENSE = 20mV l Output (V) Small signal frequency response 25 1 10 Frequency (kHz) Output (V) -20 10E+0 Output VOUT (V) Gain (dB) 20 TA = 25°C VSENSE = 50mV 60 2.30 2.25 0 Small signal positive pulse response 25 50 75 time (µs) 100 2.20 150 125 Small signal negative pulse response Pin out information Pin No. Name 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 impedance negative sense voltage input 4 S+ Positive sense input. Also acts as power supply pin to ZXCT1023 Central Paddle ZXCT1023 Rev. 2 Pin Function Substrate. Connect to GND. 4 of 7 www.diodes.com October 2009 © Diodes Incorporated 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+ RS S- RGT – + VOUT RG GND The ZXCT1023 has its gain setting resistor, RG, set at 15kΩ which further reduces power consumption at larger VSENSE. Application Examples Please refer to Zetex AN39 for sample applications. Package Outline TDFN1812-4 package ZXCT1023 Rev. 2 5 of 7 www.diodes.com October 2009 © Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1023 MICROPOWER FIXED GAIN OF 50 CURRENT MONITOR Recommended PCB Land Pattern ZXCT1023 Rev. 2 6 of 7 www.diodes.com October 2009 © 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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