RH-128
Baseband Description and Troubleshooting
COMPANY CONFIDENTIAL
Copyright © 2009 Nokia. All rights reserved.
Page 5-
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Issue 1
VDD_TCXO 2.80V 80mA
Enabled only when the system is powered on
(Off during sleep and power-off modes)
KEYPAD_LED 2.80V 100mA
Enabled when the system is powered on, or
the keys are pressed, etc.
VDD_RX
2.85V
80mA
Enabled when the receiver is on
VDD_TX
2.80V
150mA
Enabled when the transmitter is on
VDD_VIBE 3.0V 150mA
Enabled only when the system is powered on
(Off during sleep and power-off modes)
VC-TCXO
The CBP device integrates a phase-locked loop from the TCXO clock input.
The PMU optimizes TCXO operation that enables and disables appropriate circuits in the proper
sequence. The controller is enabled by the OSC_EN signal from the CBP. When the selected transition
occurs at OSC_EN, the controller quickly enables the TCXO regulator and the input buffer, and begins
counting SLEEP_CLK pulses. Within an initial power on period, the TCXO will be stabilized to its own
calibrated frequency. This initial period, in units of 32.768 kHz clock pulses, is programmed into a timer
within the controller. When the timer expires, the output buffer is enabled. It synchronizes with the
TCXO input such that the TCXO_OUT signal is glitch free, only valid TCXO pulses are output.
SLEEP Crystal Circuit for 32.768 kHz
The 32.768 kHz crystal oscillator is the primary SLEEP clock source when TCXO clocks are disabled to
save power.
Battery
The RH-128 uses a Lithium-Ion cell battery with a capacity of 860mA.CBP reads the resistor inside the
battery pack on the BSI line to identify the battery size. Different charging algorithm will be used for
