bq51050B
bq51051B
SLUSB42C –JULY 2012–REVISED FEBRUARY 2013
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TS/CTRL Function:
The TS-CTRL pin offers three functions:
1. NTC temperature monitoring,
2. Charge done indication,
3. Fault indication
When NTC is connected between TS/CTRL pin and the GND, the NTC is function is allowed to operate. If the
TS/CTRL pin is pulled to the battery voltage, the Rx is shutdown with the indication of a charge complete
condition. If the TS-CTRL pin is pulled to GND, The Rx is shutdown with the indication of a fault.
Thermal Protection
The bq5105x includes a thermal shutdown protection. If the die temperature reaches TJ(OFF), the LDO is shut
off to prevent any further power dissipation.
WPC 1.1 Compatibility
The bq5105x is a WPC 1.1 compatible device, In order to enable a Power Transmitter to monitor the power loss
across the interface as one of the possible methods to limit the temperature rise of Foreign Objects, the
bq51050B reports its Received Power to the Power Transmitter. The Received Power equals the power that is
available from the output of the Power Receiver plus any power that is lost in producing that output power. For
example, the power loss includes (but is not limited to) the power loss in the Secondary Coil and series resonant
capacitor, the power loss in the Shielding of the Power Receiver, the power loss in the rectifier, the power loss in
any post-regulation stage, and the eddy current loss in metal components or contacts within the Power Receiver.
In WPC1.1 specification, foreign object detection (FOD) is enforced, that means the bq51050B will send received
power information with known accuracy to the transmitter.
WPC 1.1 defines Received Power is “the average amount of power that the Power Receiver receives through its
Interface Surface, in the time window indicated in the Configuration Packet”.
A Receiver will be certified as WPC 1.1 only after meeting following requirement The DUT (Device Under Test) is
tested on a Reference Transmitter whose transmitted power is calibrated, the receiver must send a received
power such that:
0 < (TX PWR) REF – (RX PWR out) DUT < 250mW
This 250mW bias ensures that system will remain interoperable.
WPC 1.1 Transmitter will be tested to see if they can detect reference Foreign Objects with a Reference receiver.
WPC1.1 Specification will allow much more accurate sensing of Foreign Objects.
A Transmitter can be certified as a WPC 1.1 only after meeting the following requirement- A Transmitter is tested
to see if it can prevent some reference Foreign Objects (disc, coin, foil) from exceeding their threshold
temperature (60°C, 80°C).
Series and Parallel Resonant Capacitor Selection
Shown in Figure 2, the capacitors C1 (series) and C2 (parallel) make up the dual resonant circuit with the
receiver coil. These two capacitors must be sized correctly per the WPC v1.1 specification. Figure 25 illustrates
the equivalent circuit of the dual resonant circuit:
20
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