Sharp LC-32A28L, Service Manual

Page: 54 / 118

LC-32A28L, LC-42A48L
54
Configuration Pins
Pin Name Pin Type Dir Description
TPWR_CI2CA 55 LVTTL
8 mA
5-V tolerant
Input
Output
I
2
C Slave Address input / Transmit Power Sense Output.
At the end of power-on-reset (POR), this pin is used as an input to latch the
I
2
C sub-address. The level on this pin is latched when the POR transitions
from the asserted state to the de-asserted state. After completion of POR,
this pin is used as the TPWR output, indicating that the selected HDMI input
port is receiving an active TMDS clock. This pin has an internal pull-up to
the MICOMVCC33 power supply. If this signal is pulled-down, a 4.7K ohm
resistor should be used. NOTE: .There is a probability the POR logic may
power up and not latch the level on this pin. A software workaround is
required to determine the proper I2C slave address.
INT 52 Schmitt
Open drain
8 mA
5-V tolerant
Input
Output
Interrupt Output.
This is an open-drain output and requires an external pull-up resistor.
RSVDL
RSVDL 10
28 Reserved pin — These pins must be tied to ground with a 10 kΩ or less resistor during
normal operation. Connecting directly to ground is recommended.
CEC Pins
Pin Name Pin Type Direct
ion Description
CEC_A 50 CEC Compliant
5-V tolerant
Input
Output
HDMI compliant CEC I/O used for interfacing to CEC devices.
This signal is electrically compliant with the CEC specification. It connects
to the CEC signal of all HDMI connectors in the system.
As an input, this pin acts as a LVTTL Schmitt triggered input and is 5-V
tolerant. As an output, the pin acts as an NMOS driver with resistive pull-up.
This pin has an internal pull-up resistor.
CEC_D 51 LVTTL
Schmitt
Open drain
5-V tolerant
Input
Output
CEC interface to local system.
This pin is an open drain and requires an external pull-up resistor. This pin
typically connects to a local CPU if the CEC functions are performed by the
CPU directly, and not the CEC controller inside the device.
Power and Ground Pins
Signal Name Pin Type Description
VCC33 9, 27, 64 Power Analog and digital core VCC. Must be supplied at 3.3 V.
MICOM_VCC33 37 Output During normal mode, this pin provides 3.3 V power to an external
microcontroller. The maximum output current is 30 mA. This pin
requires 1
µ
F capacitor to ground.
SBVCC33 38 Power
3.3V standby power. If 3.3V standby mode is not used, this pin
should be left as not connected
ePAD ePad Ground ePad must be connected to Ground .
All analog and digital ground planes are tied together to the ePad,
which
must
be connected to Ground.