Motorola T720 - Battery Charging

18 © 2002 Motorola, Inc.
Circuit Description &
Theory Of Operation
T720
Personal Communications Sector
T720- CIRCUIT DESCRIPTION AND
THEORY OF OPERATION
BASEBAND OR AUDIO LOGIC SECTION
The logic part consists of (1)MSM5100 (vs
Wally in V.120C) which has an ARM7 micropro-
cessor, Qualcomm DSP, CODEC, VOCODER
and audio amplifiers integrated. Low voltage
operation: Digital Core as low as 2.3V, I/O 2.3V
to 3.0V, Analog 2.5V to 2.7V.
Basic Features Includes the Following:
CDMA Module- 1XMC,IS-95A,B IS-2000,
Digital FM module, ARM7TDMI micropro-
cessor, Vocoder (13kQCELP and EVRC),
integrated CODEC, QDSP2000, R-UIM
controller.
RF Interface: Digital Rx I/Q, Tx D/A
Peripherals and Interfaces: General pur-
pose I/O(GPIO), UART(2), USB(enhanced),
Keypad, Ringer, M/N conter, Housekeeping
A/D, Microphone amplification, Speaker
drivers, Analog “hands free kit” interface,
LCD support, JTAG for debugging.
Clock Support: PLL for 19.2 Mhz(tri-
mode) and 19.8Mhz(J-CDMA) TCXO fre-
quencies, separate PLL for Code clock.
Audio Features: Echo cancellation for
handset, head set and “hands free kit” appli-
cations, Audio AGC, Voice Recognition (2)
Qualcomm PM1000 (vs CCAP in V.120C) is
a very simple power management IC with no
integrated CODEC or audio amplifiers, it has
8 LDO voltage regulators, it doesn’t have
internal charge controller, instead it requires
external regulated voltage and current for
hardware controlled charging of Lithium Ion
batteries. NiMH charging not supported. It
doesn’t have a USB transceiver integrated,
but instead uses an USB IC and requires an
external 48Mhz PLL. Power on reset control
circuit, vibrator, LCD backlight, keypad
backlight, buzzer/ringer, and EL display
drivers. Contains RTC, and 32Khz sleep
oscillator.
• PM1000 doesn’t have CE bus multiplexers
integrated, but instead uses an ASIC called
Harness.
• LDO (Low Drop Out) Regulator Operating
Voltages
Table 5:
Linear Regulator
Nominal Volt
VREG_MSMC 2.86V
VREG_MSMP 2.83V
VREG_MSMA 2.65V
VREG_IF 2.90V
VREG_SYNTH 2.90V
VREG_TCXO 2.75
VREG_RF_RX 2.90V
VREG_RF_TX 2.90V