A Product Line of Diodes Incorporated ZXCT1030 HIGH-SIDE CURRENT MONITOR WITH COMPARATOR Description Pin Assignments The ZXCT1030 is a high side current sense monitor containing an internal reference and comparator with a nonlatching output. Using this device eliminates the need to disrupt the ground plane when sensing a load current. The wide input voltage range of 20V down to as low as 2.2V make it suitable for a range of applications. Dynamics and supply current are optimized for the processing of fast pulses, associated with switch mode applications. Features • • • • • • • Low cost, accurate high-side current sensing Output voltage scaling Up to 18V output 2.2V - 20V supply range Voltage reference on chip Comparator on chip SO8 package VCC VSENSEVSENSE+ GND VCOMP_OUT VOUT Vref_out VCOMP_IN Applications • • • • • • Battery chargers Electronic fuse DC motor control Over current monitor Power management Inrush current limiting Typical Application Circuit ZXCT1030 Document number: DS32161 Rev. 4 - 2 1 of 7 www.diodes.com June 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1030 Pin Description Pin Name Function VCC Supply voltage VSENSE- Negative sense input VSENSE+ VREF_OUT Positive sense input Ground Comparator input, usually a ratio of the reference or other control signal Reference output VOUT Current monitor output voltage VCOMP_OUT Open collector comparator output GND VCOMP_IN Absolute Maximum Ratings Parameter Voltage on any pin Operating Temperature Storage Temperature Package Power Dissipation SO8 Rating -0.6 and VCC +0.6 -40 to 85 -55 to 125 (TAMB = 25) 700 Unit V °C °C °C mW Recommended Operating Conditions Parameter Min Max Units 2.2 20 V 2.2 VCC V VSENSE 10 500 mV VOUT 0 VSENSE- -1V V 0.005 10 V -40 85 °C VCC VSENSE+ (a) VCOMP_IN TAMB ZXCT1030 Document number: DS32161 Rev. 4 - 2 2 of 7 www.diodes.com June 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1030 Electrical Characteristics (ZXCT1030N8) – Test conditions TAMB = 25°C, VIN = VCC = 15V, RCOMP = 10kΩ, VCOMP_SUPPLY = 5V unless otherwise stated. Symbol VCC VSENSE+ Parameter Condition VCC Range Sense+ Range VOUT Output Voltage ROUT Output Resistance VOUT TC ICC ISENSE+ ISENSE- VOUT Temperature Coefficient Supply Current VCM(MIN) (B) Minimum Active Common Mode Voltage ACC GAIN Accuracy BW Bandwidth VSENSE+ Input Current VSENSE- Input Current VOUT/VSENSE VSENSE = 0 VSENSE = 10 VSENSE = 30 VSENSE = 50 VSENSE = 100 VSENSE = 500 VSENSE - = 15V, VOUT = 1V Typ. VSENSE - = 15V 0 88 284 480 970 4500 2 100 300 500 1000 5000 10 112 316 520 1030 5500 mV 1.2 1.5 1.8 kΩ VSENSE- = 14.9V VCC = 15V VCOMP_SUPPLY = 5V VCOMP_IN = VREF VSENSE = 10mV VSENSE = 100mV VSENSE = 100mV VSENSE = 10mVp-p VSENSE = 100mVp-p 170 270 48 70 ppm/°C 350 90 220 2.8 -3 9.7 10.0 0.005 30 µA µA nA V 3 10.3 3 6 5 Unit V VCC % MHz 10 15 80 100 150 150 200 V mV nA ns mV VCOMP_ Output Voltage High VOH Max. 20 30 COMPARATOR Input Voltage VCOMP_IN Hysteresis VH Input Bias IB Propagation Delay TD Output Voltage Low VOL SUPPLY Output Sink Current IOL Output High Leakage Current IOH Voltage Reference VREF Delta VREF Change in VREF TC PSR Supply Rejection Notes: Min. 2.2 2.2 Vol = 0.4V Reference Current = +300µA to -5µA ISOURCE 5µA to ISINK 300µA 2 1.200 1.240 1.0 mA µA 1.280 V 10 mV 30 0.01 ppm/°C %/V (a) (VSENSE+) – (VSENSE-) (b) Level of VSENSE+ where comparator output defaults to ‘off’. ZXCT1030 Document number: DS32161 Rev. 4 - 2 3 of 7 www.diodes.com June 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1030 Typical Application Circuits ZXCT1030 Document number: DS32161 Rev. 4 - 2 4 of 7 www.diodes.com June 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1030 Voltage output current monitor Referring to the block diagram, the current monitor takes the small voltage developed across the sense resistor (VSENSE) and transfers it from the large common mode supply voltage to a ground referenced signal with a gain of 10. The sense input common mode range is 2.2V to 20V. In this range, a linear output voltage is delivered. Reference The bandgap reference allows the comparator to compare the translated VSENSE with threshold value chosen by the user which can be any voltage from 0 to 1.24V, configured by two external resistors which forms VCOMP_IN. The output current which can be drawn from the comparator reference (IREF source) is limited to 5μA, making potentiometers ≥250kΩ suitable for setting a threshold level. Where a lower potentiometer resistor value is used, an additional resistor value should be inserted between VREF and VCC to maintain sufficient current for the reference. (as shown in Figure 1). Figure 1: External Resistor for Reference Level The voltage reference has a maximum current sink capability. This magnitude of current will be influenced by the value of R1 which is inserted between VREF and VCC. The value of current flowing through R1 can be expressed as: I = (VCC -VREF) / R1 Comparator The open collector output is active low and is asserted when VSENSE x 10 (VOUT) > VCOMP_IN. It can be connected to any voltage rail up to VIN via a pull-up resistor. Suggest values for the resistor are in the range of 10-100kΩ. In the case where high load currents or a short circuit occurs, thus reducing the common mode signals (V+, V-) typically below 2.2V, the comparator will default to the asserted state. This can eliminate a closed loop system 'latch-up' condition, allowing the controller to remove the applied power. Stability To ensure stable operation of the ZXCT1030, it is recommended a decoupling capacitor is placed across the VCC and ground connections. A ceramic 10µF will be adequate. ZXCT1030 Document number: DS32161 Rev. 4 - 2 5 of 7 www.diodes.com June 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1030 Ordering Information* Device Status(*) Package ZXCT1030X8TA ZXCT1030N8TA Obsolete Active MSOP8 SO8 Notes: Device Marking ZXCT1030 ZXCT1030 Reel Size (inches) 7 7 Tape Width (mm) 12 12 Quantity Per reel 1000 500 *ZXCT1030X8TA is obsolete for more device information please check our obsolete products search on diodes website Package Outline – SO8 ZXCT1030 Document number: DS32161 Rev. 4 - 2 6 of 7 www.diodes.com June 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZXCT1030 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). 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