Description Application
ZXCT1010 is a high side current detection monitor.
Battery chargers use this device without interrupting the smart battery pack ground plane when inducing load current. DC Motor Control It is an enhanced version of the ZXCT1009 product. Over-current monitor reduces typical output deviation and improves accuracy for power management at low inductance voltage. The programmable current source has a wide input voltage range of 20V down to 2.5V making it suitable for a variety of applications. A minimum operating current of only 4 microamps, the combination is packaged in SOT23-5 , suitable for portable application circuit battery equipment.
feature 8226 ; Low Cost, Accurate High Side Current Sensing • Output Voltage Ratio • Up to 2.5 V Sense Voltage • 2.5 V–20 V Supply Range • 300na Typical Offset Current • 3.5 µA Quiescent Current • 1% Typical Accuracy • SOT23- 5 packs

Model ZXCT1010 Absolute Maximum Ratings Voltage on Any Pin -0.6V to 20V (relative to ground) Continuous Output Current, Output, 25mA Continuous Sense Voltage, Vsense2 -0.5V to +5V Operating Temperature, Ta, -40 To 85°C storage temperature -55 to 150 °C Unit power consumption (Ta=25°C) SOT23-5 300MW
Operation above the Absolute Maximum Ratings may cause device failure. Exposure to absolute maximum ratings for extended periods of time may degrade device reliability. Electrical characteristics test conditions Ta=25°C, Vin=5 V, Rout=100Ω.

Power Application Information

The maximum allowable power dissipation for the following lines describes how to scale the load device for normal operation (pmax) as a function of current versus output voltage. The package is connected to ambient thermal resistance (ja), maximum junction temperature (Tjmax) and Vsense=VIN-V load ambient temperature (tamb), according to the expression: vout=0.01 x vsense x rout1 pmax=(tjma–tamb)/ja for example The device power consumption pd is given by the 1A current, expressed by the 100 mV output expression: Voltage: pd = iout. (vin vout) watts 1) Choose the value of rsense to give 50mv>vsense>500mV at full load. For example, at 1.0a.rsense=0.1/1.0, vsense=100mV=>0.1 ohm.
When Vsense, choose Rout to give vout=100mV100mV. Rearranging 1 for Rout gives: Rout=Vout/(Vsense x 0.01)rout=0.1(0.1 x 0.01)=100Ω
Typical circuit applications where rload represents any load including a DC motor, a battery that needs to be charged or other circuit monitoring, can be specified at specific accuracy, size and power rating requirements.

Application Information (continued)

Li-ion charger circuit

Bidirectional Current Sensing
ZXCT1010 can be used to measure current bidirectionally, if two devices are connected to battery as charger input + FZT789A 140μH 0.2Ω

ZXCT1010 is equipped with Benchmarq BQ2954 charging management IC. Most of the supporting components of the BQ2954 are omitted for clarity. This design also uses the transistors in the ZetexFZT789A high current ultra-PNP switching DC-DC buck converter if the voltage v1 is relative to the fmmt451 as the driver NPN for the FZT789A. Devices with a lower voltage V2 will activate, providing the circuit can be configured to charge four Li-ions with a proportional output current used for routing. Since the charging current is 1.25A for the battery. Charge can be the polarity of the voltage on RSENSE. When terminated at maximum voltage, selectable devices will be inactive and will not time out for minimum current or maximum. The switching current is delivered to Rout. The frequency of the PWM loop is about 120kHz when V2 is more aggressive. Instead of v1, the current will flow in the opposite direction, making the upper device active in the opposite direction. The risk of nonlinearity at very small V by offsetting the current contribution. Equipment if the current direction should be independently monitored.
Two-way transfer function

Application Information (Continued) Low-Cost Printed Circuit Board Tracking Parallel Resistor Solutions Low-Cost Solutions Using PCB Resistor Tracking Devices to Replace Traditional Shunt Resistors. The graph shows a linear rise in voltage. Due to the PTC of the material and illustrating how the rise in resistance value exceeds the NTC of the temperature compensated device. Contrary to a PCB layout recommendation. The resistive section is 25 mm x 0.25 mm, giving about 150MΩ, using 1oz copper. Data For normalized graphs, 1A load current and 100Ω output resistance were used. An electronic version of the actual size printed circuit board layout is available at