P9242-R3/RB Datasheet

© 2019 Integrated Device Technology, Inc.

16

May 17, 2019

7.3 Enable Pin – EN

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The P9242-R3 can be disabled by applying a logic HIGH to the EN pin. When the voltage on the EN pin is pulled high, operation is suspended

and the P9242-R3 is placed in the low-current Shut-Down Mode. If pulled low, the P9242-R3 is active.

7.4 Voltage Demodulation – VDEM1 Pin

In order to increase the communication reliability in any load condition, the P9242-R3 has integrated two demodulation schemes, one based

on coil current information and the other based on coil voltage modulation. The voltage mode envelope detector is implemented using a discrete

solution as depicted on Figure 14. This simple implementation achieves the envelope detector function low-pass filter as well as the DC filter

function.

Figure 14. Voltage Mode Envelope Detector

Coil Voltage

(VCOIL)

D1

R14

R11 C19

R13

C22

C17

Packet

Decoder

To

Registers

P9242-R3

VDEM1

ASK Decoder

7.5 Current Demodulation – IDEMI Pin

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

20mΩ

R18

P9242-R3

R6

C9

C8

C7

ASK Decoder