SLUS892D December   2009  – December 2019

PRODUCTION DATA.

1. Features
2. Applications
3. Description
1.     Device Images
4. Revision History
5. Description (continued)
6. Device Comparison Table
7. Pin Configuration and Functions
8. Specifications
9. Detailed Description
1. 9.1 Overview
2. 9.2 Functional Block Diagram
3. 9.3 Feature Description
4. 9.4 Device Functional Modes
10. 10Application and Implementation
1. 10.1 Application Information
2. 10.2 Typical Applications
1. 10.2.1 System with Power Path
2. 10.2.2 Simplified System without Power Path or DPM
11. 11Power Supply Recommendations
12. 12Layout
13. 13Device and Documentation Support
14. 14Mechanical, Packaging, and Orderable Information

• RGE|24
• RGE|24

#### 9.3.18 Temperature Qualification

The controller continuously monitors battery temperature by measuring the voltage between the TS pin and GND. A negative temperature coefficient thermistor (NTC) and an external voltage divider typically develop this voltage. The controller compares this voltage against its internal thresholds to determine if charging is allowed. To initiate a charge cycle, the battery temperature must be within the VLTF to VHTF thresholds. If battery temperature is outside of this range, the controller suspends charge and the safety timer, and waits until the battery temperature is within the VLTF to VHTF range. During the charge cycle, the battery temperature must be within the VLTF to VTCO thresholds. If battery temperature is outside of this range, the controller suspends charge and waits until the battery temperature is within the VLTF to VHTF range. The controller suspends charge by turning off the PWM charge FETs. Figure 15 summarizes the operation.

Assuming a 103AT NTC thermistor on the battery pack as shown in Figure 20, the value RT1 and RT2 can be determined by using the following equations:

Equation 8.
Equation 9.

For example, 103AT NTC thermistors are used to monitor the battery pack temperature. Select TCOLD = 0ºC and TCUT_OFF = 45ºC; then we get RT2 = 430 kΩ, RT1 = 9.31 kΩ. A small RC filter is suggested to use for system-level ESD protection.