WM8310GEB/V Wolfson Microelectronics, WM8310GEB/V Datasheet - Page 280

• Manufacturer Part Number: WM8310GEB/V
• Description: POWER MANAGEMENT SUBSYSTEM, 169BGA
• Manufacturer: Wolfson Microelectronics

Specifications of WM8310GEB/V

• Supply Voltage: 7V
• No. Of Step-down Dc - Dc Converters: 4
• No. Of Ldo Regulators: 11
• Digital Ic Case Style: BGA
• No. Of Pins: 169
• No. Of Regulated Outputs: 13
• Operating Temperature Range: -40°C To
• Rohs Compliant: Yes
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

WM8310
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To select a specific Hot Battery threshold, the required NTC bias resistor value may be calculated
using the following equation:
For example, at 60°C the Vishay Curve 1 resistance ratio, r
Therefore, to implement a 60°C Hot Battery threshold, assuming a 100kΩ NTC thermistor (at 25°C),
the required NTC bias resistor is 46.6kΩ (nearest E12 value 47kΩ).
The resultant Cold Battery threshold is given using the r
to be referenced to the Vishay Curve 1 resistance chart in order to find the corresponding
temperature.
To select a specific Cold Battery threshold, the required NTC bias resistor value may be calculated
using the following equation:
For example, at 5°C the Vishay Curve 1 resistance ratio, r
Therefore, to implement a 5°C Cold Battery threshold, assuming a 100kΩ NTC thermistor (at 25°C),
the required NTC bias resistor is 78kΩ (nearest E12 value 82kΩ).
The resultant Hot Battery threshold is given using the r
be referenced to the Vishay Curve 1 resistance chart in order to find the corresponding temperature.
To select both the Hot Battery threshold and the Cold Battery threshold, an additional resistor, R1, is
required, as illustrated in Figure 38.
Figure 38 Battery Temperature Threshold Selection
R
r
R
R
r
R
HOT
COLD
BIAS
25
BIAS
25
is the NTC thermisor resistance at 25°C
is the NTC thermisor resistance at 25°C
is the NTC thermistor resistance ratio at the desired temperature threshold
is the NTC thermistor resistance ratio at the desired temperature threshold
= (r
= (r
HOT
COLD
/ 0.534) x R
/ 3.255) x R
25
25
HOT
COLD
COLD
HOT
equation below. The r
equation below. The r
, is 2.540.
, is 0.2488.
PP, December 2009, Rev 3.0
HOT
COLD
value needs to
Pre-Production
value needs
280