LG C570 Service Manual

LG

Service Manual

C570

Table Of Contents

1. INTRODUCTION................................…4

1.1 Purpose ..........................................….

1.2 Regulatory Information ......................

4
4

2. PERFORMANCE ..............................….6

2.1 H/W Feature ...................................…..

2.2 Technical Specification ...................... 68

3. TECHNICAL BRIEF ............................14

3.1 Transceiver (RTR6285, FU1)..........…..

3.2 Power Amplifier Module ................….

3.3 BT/WiFi (BCM4325, FU1 on SB) ………

3.4 PMIC (PM7540, U7)……………………….

3.5 Input power management…............….

3.6 MSM7227 (U1) .…………………………

3.7 MCP memory ......................…………….

3.8 LG display LCM ..............……………….

3.9 VGA CCM .....................…………………

3.10 2M CCM ........................................... .

3.11 Vibrator ......................... ………………

3.12 Optical Joystick…………………………

3.13 LCM backlight and keypad light .......

3.14 Side key and Qwerty key....................

3.15 USB PHY ……………….………………

3.16 T-Flash...................……………………

3.17 USIM..............………………………….

3.18 Receiver ………………………………..

3.19 Internal Microphone.....................…..

3.20 Speaker ………………………………..

3.21 3.5mm Ear-Mic with send/end key …

3.22 Main battery ……………………………

14
20
22
23
26
50
82
85
87
89
91
92
94
96
98

99
100
101
102
103
104
105

4. TROUBLE SHOOTING ................… 106

4.1 Hw Function Check……………………

4.2 FTM Mode in board level…….………

4.3 Wireless Trouble.............................….

4.4 WCDMA RX Trouble...........................

4.5 WCDMA TX Trouble..........................

4.6 GSM RX Trouble..........................……

4.7 GSM TX Trouble...........................…...

4.8 GPS Trouble........................................

4.9 WLAN/BT/FM Trouble........................

4.10 Power On Trouble..............................

4.11 Charging Trouble................................

4.12 LCD Trouble....................................

4.13 2M Camera Trouble.........................

4.14 VGA Camera Trouble………………

4.15 LCD backlight Trouble....................

4.16 KEYPAD Light Trouble...................

4.17 SIM Card Interface Trouble………..

4.18 T-Flash Trouble……………………..

4.19 USB Trouble ………………………..

4.20 Qwerty key Trouble………………...

4.21 Side key Trouble……………………

4.22 Vibrator Trouble…………………….

4.23 Receiver Trouble……………………

4.24 Speaker Trouble…………………….

4.25 Microphone Trouble…………………

4.26 Ear-Mic Trouble……………………...

107
108
109
113
139
157
167
180
193
204
208
211
215
219
223
226
230
233
236
240
243
248
251
256
261
264

5. DISASSEMBLY INSTRUCTION … 269

5.1 Disassembly ...............................

269

6. BLOCK DIAGRAM …....................... 281

7. CIRCUIT DIAGRAM ......................... 282

8. ONE POINT REPAIR ………....... 308

9. EXPLODED VIEW &
REPLACEMENT PART LIST ...…. 318

9.1 Exploded View ........................

9.2 Replacement parts..................

10. SERVICE ENGINEERING TOOL..... 328

318
319

11. SERVICE ENGINEERING
OPERATIONS………………………...335

11.1 User Interface ...........................…

11.2 Initial Operations .........................

11.3 Hardware Test...............................

11.4 RF Auto Test ..……………............

11.5 RF Configuration ……..................

11.6 Miscellaneous Group ...................

335
336
338
343
347
363

10.1 Instruction................................

10.2 CSE Installation ...................…

10.3 Phone Mode .....................……

10.4 Driver Installation ....................

328
329
330
331

1. INTRODUCTION

1.1 Purpose

This manual provides the information necessary to repair, calibration, description and download the
features of this model.

1.2 Regulatory Information

A. Security

Toll fraud, the unauthorized use of telecommunications system by an unauthorized part (for example,
persons other than your company’s employees, agents, subcontractors, or person working on your
company’s behalf) can result in substantial additional charges for your telecommunications services.
System users are responsible for the security of own system. There are may be risks of toll fraud
associated with your telecommunications system. System users are responsible for programming and
configuring the equipment to prevent unauthorized use. The manufacturer does not warrant that this
product is immune from the above case but will prevent unauthorized use of common-carrier
telecommunication service of facilities accessed through or connected to it.

The manufacturer will not be responsible for any charges that result from such unauthorized use.

B. Incidence of Harm

If a telephone company determines that the equipment provided to customer is faulty and possibly
causing harm or interruption in service to the telephone network, it should disconnect telephone service
until repair can be done. A telephone company may temporarily disconnect service as long as repair is
not done.

C. Changes in Service

A local telephone company may make changes in its communications facilities or procedure. If these
changes could reasonably be expected to affect the use of the this phone or compatibility with the network,
the telephone company is required to give advanced written notice to the user, allowing the user to take
appropriate steps to maintain telephone service.

D. Maintenance Limitations

Maintenance limitations on this model must be performed only by the manufacturer or its authorized agent.
The user may not make any changes and/or repairs expect as specifically noted in this manual. Therefore,
note that unauthorized alternations or repair may affect the regulatory status of the system and may void
any remaining warranty.

1. INTRODUCTION

E. Notice of Radiated Emissions

This model complies with rules regarding radiation and radio frequency emission as defined by local
regulatory agencies. In accordance with these agencies, you may be required to provide information such as
the following to the end user.

F. Pictures

The pictures in this manual are for illustrative purposes only; your actual hardware may look slightly different.

G. Interference and Attenuation

Phone may interfere with sensitive laboratory equipment, medical equipment, etc.Interference from
unsuppressed engines or electric motors may cause problems.

H. Electrostatic Sensitive Devices

ATTENTION
Boards, which contain Electrostatic Sensitive Device (ESD), are indicated
by the sign. Following information is ESD handling:

• Service personnel should ground themselves by using a wrist strap when exchange system

boards.

• When repairs are made to a system board, they should spread the floor with anti-static mat

which is also grounded.

• Use a suitable, grounded soldering iron.

• Keep sensitive parts in these protective packages until these are used.

• When returning system boards or parts like EEPROM to the factory, use the protective

package as described.

2. PERFORMANCE

2.1 H/W Features

Item Feature Comment

Standard Battery

Li-ion, 1500mAh
Battery Size : 65.3 (W) × 44(H) × 5.2(T) [mm]
Battery Weight : 31g

Standby Current

Talk time

Stand by time

Charging time Under 240 min

RX Sensitivity

TX maximum

output power

GPRS compatibility Class 12

SIM card type 3V & 1.8V

Display

Key

ANT Internal

WCDMA w/o BT: Under 3 mA (DRX=1.28)
GSM w/o BT: Under 3mA (Paging= 5 period)

WCDMA: Over 300 min (TX = 12dBm low)
GSM: Over 270min (TX= Lvl 5)

WCDMA: Over 450 hours (DRX = 1.28)
GSM: Over 450hours (Paging = 5 Period)

WCDMA: -106.7dBm/3.84MHz
GSM: -105dBm(2.439%)

WCDMA:+24dBm+1/-3 db (Power class3)/ 3.84MHz
GSM: +33dBm ± 3dB, DCS/PCS: +30dBm ± 3dB

2.4” 320 x 240 TFT LCD

Full Qwerty keypad

EAR Phone Jack Yes (stereo)

PC Synchronization Yes

Speech coding

Data and Fax

Vibrator Yes

Loud Speaker Yes

Voice Recoding Yes

Microphone Yes

EFR/FR/HR

2. PERFORMANCE

Item Feature Comment

Speaker/Receiver Single speaker with Speaker/Receiver two mode

Travel Adapter Yes

MIDI 64 poly

MP3/AAC Yes

Options Data Cable

2. PERFORMANCE

2.2 Technical Specification

Item Description Specification

GSM850: 824~849MHz/869~894MHz
GSM900: 880~915MHz/925~960MHz
DCS: 1710~1785MHz/1805~1880MHz

1 Frequency Band

2 Phase Error GSM: RMS : 5°, Peak : 20 °

PCS: 1850~1910MHz/1930~1990MHz
WCDMA850:824 MHz ~ 849 MHz/869~894MHz
WCDMA900 :880 MHz ~ 915 MHz/925~960MHz
WCDMA1900:1850 ~1910 MHz/1930~1990MHz
WCDMA2100:1920 MHz~1980 MHz/2110~2170MHz

3 Frequency Error

4 Power Level

GSM : 0.1 ppm
WCDMA: ±(0.1ｐｐｍ+10Hz)

GSM850

Up LimitLow LimitPowerPower level

3331325

3230316

3028297

2925278

2723259

25212310

23192111

21171912

19151713

17131514

15111315

1481116

126917

104718

82519

2. PERFORMANCE

Item

Description

Specification

DCS1800/PCS 1900

Up LimitLow LimitPowerPower level

30 28290

2927281

2725262

2622243

2420224

2218205

2016186

1814167

1612148

159129

1371010

115811

4 Power Level

93612

71413

5-1214

3-3015

WCDMA850

Up LimitLow LimitPowerPower level

252122.5 Max

WCDMA900

Up LimitLow LimitPowerPower level

252122.2Max

WCDMA1900

Up LimitLow LimitPowerPower level

252122.2 Max

WCDMA2100

Up LimitLow LimitPowerPower level

25 2122.2 Max

2. PERFORMANCE

Item Description Specification

GSM850 & 900

Offset from Carrier (kHz). Max. dBc

100 +0.5

200 -30

250 -33

400 -60

600~ <1,200 -60

1,200~ <1,800 -60

1,800~ <3,000 -63

3,000~ <6,000 -65

5

6

Output RF Spectrum
(due to modulation)

Output RF Spectrum
(due to switching

transient)

Offset from Carrier (kHz). Max. dBc

Offset from Carrier (kHz). Max. dBm
Offset from Carrier (kHz). Max. dBm

6,000 -71

DCS & PCS

100 +0.5

200 -30

250 -33

400 -60

600~ <1,200 -60

1,200~ <1,800 -60

1,800~ <3,000 -65

3,000~ <6,000 -65

6,000 -73

ＧＳＭ９００/ＧＳＭ８５０

GSM850 & 900

400 -１9

400 -19

600 -2１

600 -21

1,200 -2１

1,200 -21

1,800 -2４

2. PERFORMANCE

Item Description Specification

DCS & PCS

Offset from Carrier (kHz). Max. dBm

Output RF Spectrum

6

7 Spurious Emissions Conduction, Emission Status

8 Bit Error Ratio

9 RX Level Report Accuracy ±3 dB

10 SLR 14±3 dB

(due to switching

transient)

GSM850 & 900

BER (Class II) < 2.439% @-102 dBm

DCS & PCS

BER (Class II) < 2.439% @-102 dBm

WCDMA

BER < ０.１% @-10６.７ dBm <ＲＥＦＩｏｒ>

Frequency (Hz) Max.(dB) Min.(dB)

400 -22

600 -24

1,200 -24

1,800 -27

11 Sending Response

12 RLR 3±3 dB

100 -

200 -

300 -12

1,000 -6

2,000 -6

3,000 -6

3,400 -9

4,000 -

-12

0

0

0

4

4

4

0

2. PERFORMANCE

Item Description Specification

Frequency (Hz) Max.(dB) Min.(dB)

13 Receiving Response

* Mean that Adopt a straight line in between 300 Hz

and 1,000 Hz to be Max. level in the range.

14 STMR >17 dB

100 -

200 -

300 -7

500 -5

1,000 -5

3,000 -5

3,400 -10

4,000

-12

0

2

*

0

2

2

2

15

16 32.768KHz tolerance

17 Ringer Volume

System frequency
(13MHz tolerance)

≤ 2.5 ppm

≤30 ppm

At least 58 dB under below conditions:

1. Ringer set as ringer.

2. Test distance set as 100 cm

2. PERFORMANCE

Item Description Specification

21 Charge Current

normal Charge : 600 mA

pre Charge : 80 mA

BAR WCDMA GSM

22 Antenna Display

BAR 4 -->

3

BAR 3 -->

2

BAR 2 -->

1

BAR 1 -->

0

-82 ±

3dBm

-92 ±

3dBm

-102 ±

3dBm

-112 ±

3dBm

23 Battery Indicator

24 Low Voltage Warning Battery Capacity < 8%

-91 ±
2dBm

-96 ±
2dBm

-101 ±
2dBm

-106 ±
2dBm

SpecificationBattery Bar

100%BAR 4 --> 3

50%BAR 3 --> 2

20%BAR 2 --> 1

8%BAR 1 --> 0

20%Low Battery Alarm

8%Critical Low Battery Alarm

0%POWER OFF

25

Forced shut down
Voltage

26 Battery Type

27 Travel Charger

3.5 ± 0.03V

1 Li-ion Battery
Standard Voltage = 3.7 V
Battery full charge voltage = 4.2 V
Capacity: 830mAh

Switching-mode charger
Input: 100 ~ 240 V, 50/60 Hz
Output: 5.1 V, 700 mA

3. TECHNICAL BRIEF

3.1 Transceiver (RTR 6285, FU1)

The RF parts consist of a transmitter part, a receiver part, a frequency synthesizer part, a voltage supply
part, and a VCTCXO part.
The RTR6285 transceiver is the integrated GSM/UMTS multi-band and multi-mode digital cellular
handsets and wireless data modems. The integrated solution also includes the GPS demodulator and the
low noise amplifier (LNAs) for UMTS and GSM RX path. The GPS LNA, RF voltage controlled oscillator
(VCO) modules, and other discrete components found in conventional designs.

Figure 3-1 RTR6285 block diagram

3. TECHNICAL BRIEF

(1) Receiver Part

The RTR6285/RTR6280 receive paths include four GSM/EDGE Rx signal paths that support
GSM 850, GSM 900, GSM 1800, and GSM 1900 bands and four WCDMA Rxsignal paths (two
single-ended and two differential) for one UMTS low band and three UMTS high bands.

A. RF front end – Antenna Switch Module(ASM, FS1)

The quad-band GSM/EDGE Rx paths start from the handset front-end circuits (GSM Rx filters
and antenna switch module) FS1. The ASM (FS1) is used to control the Rx and Tx paths. And,
the input signals VC1, VC2, VC3 and VC4 of a FS1 are directly connected to baseband
controller to switch either Tx or Rx path on.The control logic is given below Table 3-1.

Table 3-1 THE ASM control logic

The four differential inputs are amplified with gain-stepped LNA circuits. Gain control is
provided through software and serial interface. The LNA outputs drive the RF ports of
quadrature RF-to-baseband downconverters. The downconverted baseband outputs are
multiplexed and routed to lowpass filters (one I and one Q) whose passband and stopband
characteristics supplement MSM device processing. These filter circuits allow DC offset
corrections, and their differential outputs are buffered to interface with the MSM IC. Figure 3-2
is GSM RX path from ASM to RTR6285.

3. TECHNICAL BRIEF

Figure 3-2 THE GSM RX path

3. TECHNICAL BRIEF

The two RTR6285/RTR6280 UMTS single-ended inputs accept UMTS 2100/1900/1800/1700
input signals from the handset RF front-end filters. The UMTS Rx inputs are provided with
on-chip LNAs that amplify the signal before second-stage filters that provide differential
signals to a shared downconverter. This second-stage input is configured differentially to
optimize second-order intermodulation and common mode rejection performance. The gain of
the UMTS front-end amplifier and the UMTS second-stage differential amplifier is adjustable,
under MSM system chip control, to extend the dynamic range of the receivers. Figure 3-3 is U
MTS RX path from ASM to RTR6285.

Figure 3-3 THE UMTS RX path

B. GPS
The GPS input path is followed by a dedicated downconverter. The GPS downconverter and
secondary WCDMA downconverter outputs are multiplexed to drive a single set of baseband
filter and buffer circuits. The secondary baseband output (in-phase and quadrature differential
signals) is routed through the DRX_I/Q pins to the MSM device for further processing. This
baseband interface supports either the WCDMA or GPS mode, whichever is active on the
secondary path.

Figure 3-4 THE GPS RX path

3. TECHNICAL BRIEF

(2) Transmitter Part

The transmit path begins with differential baseband signals (I and Q) from the MSM device.
These analog input signals are buffered, filtered by low-path filter, corrected for DC offsets,
amplified, and then applied to the quadrature upconverter mixers.
The upconverter outputs are amplified by multiple variable gain stages that provide transmit
AGC control. SSBI is used to do the gain control. The specified driver amplifier output level is
achieved while supporting the GSM/EDGE and UMTS transmit standard’s requirements for GSM
ORFS, carrier and image suppression, WCDMA ACLR, spurious emissions, Rx-band noise, etc.
These upconverters translate the polar GMSK-modulated or 8-PSK modulated baseband PM
signals and/or WCDMA baseband signals directly to the RF signals, which are filtered and feed
into the GSM/EDGE polar PA and/or WCDMA PA.
The WCDMA Tx power is coupled back to the RTR6285/RTR6280 internal power detector input
pin, PWD_DET_IN, using a coupler for power measurement.

Figure. 3-5 RTR6285 TRANSMITTER PART

(3) PLLs

Three fully functional fractional-N synthesizers, including VCOs and loop filters, are integrated
within the RTR6285 IC, while the RTR6280 IC has two fractional-N synthesizers. The first
synthesizer (PLL1) creates the transceiver LOs that support the UMTS transmitter, and all four
GSM band receivers and transmitters including: GSM 850, GSM 900, GSM 1800, and GSM

1900.
The second synthesizer (PLL2) provides the LO for the UMTS primary and secondary receivers
(RTR6285 only). The third synthesizer (PLL3) provides the LO for the GPS receiver

3. TECHNICAL BRIEF

N

N

Counter

Counter

VCO

VCO

Digital

Logic

Control signal

R

Loop filter

Loop filter

Figure. 3-6 RTR6285 PLLs Block Diagram

(4) Baseband interface

The RTR6285 IC provides the I/Q path to connect MSM system chip for UMTS/GSM TX and RX sig
nals.
The RF IQ signals are demodulated in MSM system chip to data stream then processed by baseba
nd system.
Most control and status commands are communicated through the RTR6285 MSM device-compati
ble SSBI, enabling efficient initialization, WCDMA transmit gain control, control of device operating
modes and parameters, verification of programmed parameters, and frequency lock status reports.
The MSM device SSBI controller is the master while the RTR6285 IC is a slave.

The RTR6285 IC also provides a digital I/O pin for time-critical control signal.

Phase detection

& charge pump

Counter

TCXO

Figure. 3-7 RTR6285 Baseband Interface

3. TECHNICAL BRIEF

3.2 Power Amplifier Module

(1) GSM PA (TQM7M5012H, FAR4)

The TQM7M5012H is a ultra-small (5x5mm), GSM/EDGE Polar PAM for handset applications. This
module has been optimized for excellent EDGE efficiency, Rx band noise performance, ACPR and
EVM in an open loop polar modulation environment at EDGE class E2+ operation while maintaining
high GSM/GPRS efficiency.
High reliability is assured by utilizing TriQuint’s 3rd generation InGaP HBT technology and by
TriQuint’s proven module design techniques.

DCS/PCS in

GSM 850/900 in

(2) UMTS PA (FAR3 / SKY17787, FAR2 / SKY77188, FAR1)

A. Band I -- SKY77186, FAR3
The SKY77186 Power Amplifier Module (PAM) is a fully matched 10-pad surface mount module

developed for Wideband Code Division Multiple Access (WCDMA) applications. This small and
efficient module packs full 1920–1980 MHz bandwidth coverage into a single compact package.
Because of high efficiencies attained throughout the entire power range, the SKY77186 delivers
unsurpassed talk-time advantages. The SKY77186 meets the stringent spectral linearity
requirements of High Speed Downlink Packet Access (HSDPA) data transmission with high power
added efficiency. A directional coupler is integrated into the module thus eliminating the need for
any external coupler.

DCS/PCS out

Logic

Power control

GSM 850/900

out

Figure 3-8 GSM PA Functional Block Diagram

3. TECHNICAL BRIEF

B. Band II -- SKY77187, FAR2
The SKY77187 Power Amplifier Module (PAM) is a fully matched 10-pad surface mount module

developed for Wideband Code Division Multiple Access (WCDMA) applications. This small and
efficient module packs full 1850–1910 MHz bandwidth coverage into a single compact package.
Because of high efficiencies attained throughout the entire power range, the SKY77187 delivers
unsurpassed talk-time advantages. The SKY77187 meets the stringent spectral linearity
requirements of High Speed Downlink Packet Access (HSDPA) data transmission with high power
added efficiency. A directional coupler is integrated into the module thus eliminating the need for
any external coupler.

C. Band V -- SKY77188, FAR1

The SKY77188 Power Amplifier Module (PAM) is a fully matched 10-pad surface mount module
developed for Wideband Code Division Multiple Access (WCDMA) applications. This small and effic
ient module packs full 824–849 MHz bandwidth coverage into a single compact package. Because
of high efficiencies attained throughout the entire power range, the SKY77188 delivers unsurpasse
d talk-time advantages. The SKY77188 meets the stringent spectral linearity requirements of High
Speed Downlink Packet Access (HSDPA) data transmission with high power added efficiency. A dir
ectional coupler is integrated into the module thus eliminating the need for any external coupler.

Figure 3-9 UMTS PA Block Diagram

3. TECHNICAL BRIEF

3.3 BT/WiFi/FM (BCM4329, FU1 on Sub board)

The BCM4329 family of single chip devices provides for the highest level of integration for a
mobile or handheld wireless system, with integrated IEEE 802.11 a/b/g, Bluetooth 2.1 + Enhanced
Data Rate (EDR), and FM radio receiver. It provides a compact ultra-small form-factor solution
with minimal external components to drive the costs for mass volumes and allows for flexibility in
size, form, and function of handheld devices. BCM4329 is designed to address the needs of
highly mobile devices that require minimal power consumption and reliable operation.
The BCM4329’s integrated CMOS WLAN 2.4 GHz and 5 GHz power amplifier provide sufficient out
put power to meet the needs of most WLAN devices. Furthermore, the BCM4329’s integrated
buck-boost regulator allows its internal power amplifiers to operate at optimal performance, even
at low Vbat supply voltages.

Figure 3-10 BCM4329 System Diagram

3. TECHNICAL BRIEF

3.4 PMIC (PM7540, U7)

 Complete power management, housekeeping, and user interface functions for wireless

devices.

1. Input power management.

z Valid external supply attachment and removal detection
z Supports unregulated external charger supplies and USB supplies as input power

source.

z Supports Lithium-ion main batteries.
z Trickle, constant current, constant voltage, and pulsed charging of the main battery.
z Support coin cell backup battery (including charging)
z Battery voltage detectors with programmable thresholds.
z VDD collapse protection.
z Charger current regulation and real-time monitoring for over current protection.
z Charger transistor protection by power limit control.
z Control drivers for two external pass transistors and one external battery MOSFET.
z Voltages, current and power control loop.
z Automated recovery for sudden momentary power loss.

2. Output voltage regulation

z One boost switch-mode power supply for driving white LED and hosting USB-OTG.
z Four buck, switch-mode power supplies for efficiently generating MSMC1, MSMC2,

MSME and PA supply voltages.

z Supports dynamic voltage scaling (DVS) for MSMC1, MSMC2 and PA outputs.
z 18 low dropout regulator circuits with programmable output voltages, implemented

using three different current ratings: 300mA(four), 150mA(ten) and 50mA(four).

z One MIC bias regulator circuit.
z All regulators can be individually enable /disable for power savings.
z Low-power mode available on most regulators.
z All regulated outputs are derived from a common bandgap reference.

3. Integrated handset-level housekeeping functions reduces external parts count, size and
cost.

z Analog multiplexer selects form five internal and up to 28 external inputs.
z Multiplexer output’s offset and gain are adjusted, increasing the effective ADC

resolution.

z Adjusted multiplexer output is buffered and routed to an MSM device ADC.
z Dual oscillators: a 32.768 kHz off-chip crystal and on-chip RC assure MSM device

sleep clock.

z Crystal oscillator detector and automated switch-over upon lost oscillation.
z Real-time clock tracking time and generating associated alarms.
z ON-chip adjustments minimize crystal oscillator frequency errors.
z Control TCXO warm-up and synchronize, deglitch and buffer the TCXO signal.
z TCXO buffer control for optimal QPH/catnap timing.
z

Multistage over temperature protection.

3. TECHNICAL BRIEF

4. Integrated handset-level user interfaces
z Four programmable current sinks recommended as keypad backlight,LCD backlight,

camera flash, and general-purpose drivers.

z Vibration motor driver programmable from 1.2 to 3.1 in 100mV increments.
z Two-channel speaker driver with programmable gain, turn-on time, and muting;

configurable inputs and outputs capable of stereo or mono operation.

z Video (TV) amplifier allows use as a camcorder or for slide presentations.

5. IC-level interfaces

z Configurable SBI for efficient initialization, status, and control
z Supports MSM interrupt processing with an internal manager.
z Many functions monitored and reported through real-time and interrupt status signals.
z Dedicated circuits for controlled power-on sequencing, including the MSM device’s

reset signal.

z Several events continuously monitored for triggering power-on/power-off sequences.
z Supports and orchestrates soft resets.
z USB-OTG transceiver for full-speed and low-speed interfacing of the MSM device to

computers as a USB peripheral, or connecting the MSM device to other peripherals.

z Two sets of RUIM level translators enable MSM device interfacingwith external

modules.

6. 22 multipurpose pins that can be configured as digital or analog I/Os, bidirectional I/Os,

or current sinks; default functions support the two sets of RUIM level translators, power­on circuit, analog multiplexer inputs, an LED driver, and a selectable reference voltage
output.

7. Highly integrated functionality in a small package- 137pin CSP with a several center

ground pins for electrical ground, mechanical stability, and thermal relief.

3. TECHNICAL BRIEF

Figure 3-12 PM7540 function block Diagram

3. TECHNICAL BRIEF

3.5.1 Input power management.

A valid analog voltage at this pin is recognized by the PM7540 IC

VCHG

to be an external supply, and factors into the IC's power
management operating mode.

CHG_CTL_N

USB_VBUS

USB_CTL_N

ISNS_P

ISNS_M

BAT_FET_N

VBAT

VCOIN

V_BACKUP

Control signal for the external pass transistor - a low voltage turns
on the pass transistor.

This pin is configured as an analog input or an analog out
depending upon the type of peripheral device connected. (Don’t use
in the C570)

Control signal for the external USB pass transistor - a low voltage
turns on the pass transistor. (Don’t use in the C570)

The positive current sensor input - connect to the pass transistor
side of the sensor resistor.

The negative current sensor input - connect to the VDD side of the
sensor resistor.

Control signal to the external battery MOSFET; connect directly to
its gate.

Monitors the battery voltage; connect directly to the battery plus
terminal

Connection to the optional coin cell. Provides backup power to the
crystal oscillator and real time clock circuits to maintain time and
alarm functions if a valid external supply or main battery is not
connected.

Connect this pin to the SRAM supply pin. (Don’t use in the C570)

Table 3-1 Input Power Management Pin Description

3. TECHNICAL BRIEF

A. Input circuit schematic diagram

Figure 3-13 Input circuit schematic diagram

3. TECHNICAL BRIEF

B. External supply detection.

The PM7540 continually monitors external supply voltages (VCHG and VUSB) and the
handset supply voltage (VDD). Internal detector circuit measure these voltages to
recognize when supplies are connected or removed, and verify they are within their valid
ranges when connected.
The PMIC detects when the external supply is removed by monitoring the voltage across
the external PNP pass transistor. The detection circuit begins to close the pass transistor
when the VCHG voltage drops to about 30mV, the detection circuitry cuts the bias to the
pass transistor sp that the removal can be detected.

C. Transistor drivers

Control drivers for the charger pass transistor and the battery MOSFET are included
within the PM7540 device. The driver outputs are applied to the external devices via the
PMIC’s CHG_CTL_N, USB_CTL_N, and BAT_FET_N pins.

D. Voltage regulator

The PM7540 device provides closed-loop control of the pass transistor (via CHG_CTL_N)
to regulate either the handset supply voltage (VDD) when not charging, or the main
battery final voltage (VBAT) when charging. When fast charging is disable, the battery
MOSFET is opened and the voltage regulation point is the ISNS_M pin (VDD). When fast
charging is enable, the VBAT pin is the voltage regulation point.

E. Current regulator

An external sensor resistor is required and must be connected across the ISNS_P and
ISNS_M pins to allow the PM7540 IC to continuously monitor the total handset
electronics plus charger current. If the programmed current threshold is exceeded, the
active pass transistor is forced to a high resistor, disrupting VDD or VBAT regulation but
protecting against excess current.
The same circuits are used to regulate the total handset electronics plus charging
current during the main battery’s constant current charging mode. Either pass transistor
(charger) can be active while the current is regulated----only the appropriate control
pin (CHG_CTL_N) is active.

3. TECHNICAL BRIEF

F. Main battery charging

The PM7540 device provides support circuitry for charging a lithium-ion battery, cycling
through as many as four charging techniques: Trickle, constant current, constant voltage
and pulsed.
Charging of a severely depleted battery begins with trickle charging, a mode that limits th
e current and avoids pulling VDD down. Once a minimum battery voltage is established u
sing trickle charging, contact current charging is enable via software to charge the batter
y quickly—this mode is sometimes called fast charging. Once the lithium-ion battery app
roaches its target voltage, the charge is completed using constant voltage.

G. Backup battery charging

Backup battery charging is enable through software control and powered from VBAT. The
on-chip charger is implemented using a programmable voltage regulator and a program
mable series resistor. The MSM device reads the backup battery voltage through the PMI
C’ s analog multiplexer to monitor charging.

3. TECHNICAL BRIEF

H. Trickle charging

Trickle charging of main battery, enable through MSM control and powered from VDD, is
provide by PM7540 IC. This mode is used to raise a severely depleted battery’s voltage t

o a level sufficient to begin fast charging.

Figure 3-14 Trickle charging