P9242-R Datasheet

© 2016 Integrated Device Technology, Inc

15

December 16, 2016

7.5

Current Demodulation – IDEMI

The current-mode detector takes the modulation information from the current sense resistor, which carries the coil current modulation

information in addition to the averaged input current. There is an additional discrete low-pass filter and DC filter between the ISNS_OUT and

IDEMI pins. The packet decoder block is shared between the voltage-mode and current-mode detectors. The packet decoder selects either

voltage-mode or current-mode signals depending upon which produces the best demodulated signal.

Figure 15. Current Mode Envelope Detector

VIN

Vbridge

Packet

Decoder

To Registers

20m

P9242-R

R1

C1

C2

C3

7.6

Thermal Protection

The P9242-R integrates thermal shutdown circuitry to prevent damage resulting from excessive thermal stress that may be encountered

under fault conditions. This circuitry will shut down or reset the P9242-R if the die temperature exceeds a threshold to prevent damage

resulting from excessive thermal stress that might be encountered under fault conditions. An internal temperature protection block is enabled

in the P9242-R that monitors the temperature inside the chip. If the die temperature exceeds 140°C, the chip shuts down and resumes when

the internal temperature drops below 120°C.

7.7

External Temperature Sensing – TS

The P9242-R has a temperature sensor input, TS, which can be used to monitor an external temperature by using a thermistor. The built-in

comparator’s reference voltage was chosen to be 0.6V in the P9242-R, and it is used for monitoring the voltage level on the TS pin.

Figure 16. NTC Thermistor Connection to TS Pin

C1

LDO33

TS

P9242-R

ADC

To disable the thermistor, the TS pin should be connected to the LDO33 pin. Do not leave the TS pin floating.

7.8

LEDs Pattern Selection – LED_PAT

The P9242-R uses two LEDs to indicate the power transfer status, faults and operating modes. LEDs are connected to LED1 and LED2 pins

as shown on the typical application schematic Figure 24.

The LED patterns can be programmed by setting the voltage on the LED_PAT pin through the resistor divider R43 and R44 as shown on

Figure 24.