Data Sheet

Freescale Semiconductor
Technical Data
Document Number: MC34825
Rev 4.0, 9/2014
Micro-USB Interface IC
Supporting Universal Charging
Solution and Wired Accessories
34825
The 34825 is designed to support the Universal Charging Solution
(UCS) recommended by the OMTP (Open Mobile Terminal Platform),
as well as to use the same 5-pin micro or mini-USB connector for other
wired accessories. The 34825 supports various types of external power
supplies to charge the battery, such as a dedicated AC/DC adapter or
a USB port. It has functions built-in to identify the type of the power
supply, and sets low or high charging current, based on the current
capability of the power supply. The 34825 monitors the power supply,
and offers an up to 28 V of overvoltage protection (OVP) to the cell
phone against failed power supplies. The 34825 also contains analog
switches to multiplex the five pins, to support UART and high speed
USB data communication, mono or stereo audio headset with or without
a microphone and a cord remote controller, manufacturing or researchand-development (R/D) test cables, and other accessories.
The 34825 monitors both the VBUS status and the resistance
between the ID pin and the ground to identify the accessory being
plugged into the mini or micro-USB connector. A high-accuracy 5-bit
ADC is offered to distinguish 32 levels of ID resistance that are
assigned to buttons in a cord remote controller or to identification (ID)
resistors of accessories. After identifying the attached accessory, the
34825 sends an interrupt signal to a host IC and the host IC can
configure the analog switches via an I2C serial bus for further actions.
When the accessory is detached from the cell phone, an interrupt signal
is also sent to inform the host. This device is powered using
SMARTMOS technology.
Features
• Identifies various types of power supplies to set low or high batterycharging current levels
• Internal power switch to offer OVP against up to 28 V failed power
supply input
• Supports stereo/mono headset with or without microphone and
remote controller with pure passive components
• Supports USB or UART R/D test cables
• High-speed (480 Mbps) USB 2.0 compliant
• Supports 32 ID resistance values with a high accuracy 5-bit ADC
• Accessory attachment and detachment detection with an interrupt
signal to the host IC
• I2C interface
• 10 A quiescent current in Standby mode
Baseband
GPIO
I2C
UART
USB XCVR
AUDIO
INTERFACE IC
(PB-FREE)
98ASA00716D
20-PIN QFN
Applications
• Cell phones
• MP3/MP4 players
• Portable voice recorders
• USB universal charging solution (USC-OMTP)
• Supports mini/micro - USB connector
• UART and USB high speed communication
• Remote control/accessories IDs
34825
VDDIO
VDD
INT
I2C_SDA
I2C_SCL
RXD
ISET
TXD
OUT
D+
VBUS
DSPK_L
ID
SPK_R
DP
MIC
DM
GND
LI+
Charger
VBUS
ID
D+
DGND
USB Connector
Figure 1. 34825 Simplified Application Diagram
© Freescale Semiconductor, Inc., 2010 - 2014. All rights reserved.
ORDERABLE PARTS
ORDERABLE PARTS
Table 1. Orderable Part Variations
Part Number (1)
Temperature (TA)
Package
MC34825EP
-40 °C to 85 °C
3.0 mm x 3.0 mm UTQFN
Notes
1. To order parts in Tape and Reel, add the R2 suffix to the part number.
34825
2
Analog Integrated Circuit Device Data
Freescale Semiconductor
INTERNAL BLOCK DIAGRAM
INTERNAL BLOCK DIAGRAM
VDDIO
Reset
OSC
Internal
Supplies
VBUS
Detect
I2C_SDA
2
I C_SCL
INT
RXD
TXD
I2 C
Interface
Interrupt
VDD
VBUS
Gate
Drive &
OCP
Registers
and
State
Machine
OUT
ISET
DP
UART
Switches
DM
ID
D+
DSPK_R
SPK_L
MIC
USB
Switches
ID ADC
Audio
Switches
ID
Detect
VBUS
GND
Figure 2. 34825 Simplified Internal Block Diagram
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
3
PIN CONNECTIONS
DP
DM
VBUS
ISET
20
19
18
17
16
SPK_R
1
15
OUT
SPK_L
2
14
I2C_SCL
MIC
3
13
I2C_SDA
D+
4
12
INT
D-
5
11
VDD
6
7
8
9
10
TXD
NC
VDDIO
NC
21
GND
RXD
TRANSPARENT
TOP VIEW
ID
PIN CONNECTIONS
Figure 3. 34825 Pin Connections
A functional description of each pin can be found in the Functional Pin Description section on page 14.
Table 2. 34825 Pin Definitions
Pin Number
Pin Name
Pin Function
Formal Name
Definition
1
SPK_R
Input
2
SPK_L
Input
Speaker left channel
3
MIC
Output
Microphone output
4
D+
IO
D+ of the USB
transceiver
D+ line of the USB transceiver
5
D-
IO
D- of the USB
transceiver
D- line of the USB transceiver
6
RXD
Output
UART receiver
Receive line of the UART
7
TXD
Input
UART transmitter
Transmit line of the UART
8
NC
No Connection
No Connection
9
VDDIO
Input
IO power supply
10
NC
No Connection
No Connection
11
VDD
Input
Power supply
12
INT
Output
Interrupt output
Open-drain interrupt output
13
I2C_SDA
IO
I2C data
Data line of the I2C interface
14
I2C_SCL
Input
I2C clock
Clock line of the I2C interface
15
OUT
Output
Power output
16
ISET
Output
17
VBUS
Input
Speaker right channel Right channel input for speaker signals
Left channel input for speaker signals
Microphone output to the baseband of the cell phone system
No Connection
IO supply voltage. The VDDIO voltage is used as the reference voltage
for the I2C bus signals. This pin also functions as a hardware reset to
the IC.
No Connection
IC power supply input
The output of the power MOSFET pass switch
Charge current setting Open-drain output to set the charger current
VBUS power supply
VBUS line of the Mini or micro-USB connector
34825
4
Analog Integrated Circuit Device Data
Freescale Semiconductor
PIN CONNECTIONS
Table 2. 34825 Pin Definitions (continued)
Pin Number
Pin Name
Pin Function
Formal Name
Definition
18
DM
IO
D- of the USB
connector
D- line of the mini or micro-USB connector
19
DP
IO
D+ of the USB
connector
D+ line of the mini or micro-USB connector
20
ID
Input
ID of the USB
connector
ID pin of the mini or micro-USB connector
21
GND
Ground
Ground
Ground
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
5
ELECTRICAL CHARACTERISTICS
MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
MAXIMUM RATINGS
Table 3. Maximum Ratings
Exceeding these ratings may cause a malfunction or permanent damage to the device.
Ratings
Symbol
Value
Unit
ELECTRICAL RATINGS
Input Voltage Range
VBUS Pin
V
OUT Pin
SPK_L, SPK_R, DP, and DM Pins
VBUS
-0.3 to 28
VOUT
-0.3 to 8.0
-2.0 to VDD+0.3
All Other Pins
-0.3 to 5.5
ESD Voltage (2)
Human Body Model (HBM) for VBUS, DP, DM, ID Pins
V
VESD
8000
Human Body Model (HBM) for all other pins
2000
Machine Model (MM)
200
THERMAL RATINGS
Operating Temperature
Ambient
°C
Junction
Storage Temperature
TA
-40 to +85
TJ
150
TSTG
-65 to +150
RJC
6.0
RJA
45
TPPRT
Note 5
(3)
Thermal Resistance
Junction-to-Case
°C/W
Junction-to-Ambient
Peak Package Reflow Temperature During Reflow
°C
(4), (5)
°C
Notes
2. ESD testing is performed in accordance with the Human Body Model (HBM) (CZAP = 100 pF, RZAP = 1500 ), and the Machine Model
(MM) (CZAP = 200 pF, RZAP = 0 ).
3.
4.
5.
Device mounted on the Freescale EVB test board per JEDEC DESD51-2.
Pin soldering temperature limit is for 10 seconds maximum duration. Not designed for immersion soldering. Exceeding these limits may
cause malfunction or permanent damage to the device.
Freescale’s Package Reflow capability meets Pb-free requirements for JEDEC standard J-STD-020C. For Peak Package Reflow
Temperature and Moisture Sensitivity Levels (MSL), go to www.freescale.com, search by part number [e.g. remove prefixes/suffixes and
enter the core ID to view all orderable parts (i.e. MC33xxxD enter 33xxx)], and review parametrics.
34825
6
Analog Integrated Circuit Device Data
Freescale Semiconductor
ELECTRICAL CHARACTERISTICS
STATIC ELECTRICAL CHARACTERISTICS
STATIC ELECTRICAL CHARACTERISTICS
Table 4. Static Electrical Characteristics
Characteristics noted under conditions VDD = 3.6 V, VBUS = 5.0 V, VDDIO = 3.0 V, -40 °C  TA  85 °C (see Figure 1), unless
otherwise noted. Typical values noted reflect the approximate parameter means at VDD = 3.6 V and TA = 25 °C under nominal
conditions, unless otherwise noted.
Characteristic
Symbol
Min
Typ
Max
Unit
VDD
2.7
-
5.5
V
-
2.5
2.65
V
-
100
-
mV
-
9.0
12
POWER INPUT
VDD Supply Voltage
VDD Power-On-Reset Threshold
Rising edge
VVDDPOR
Hysteresis
VDD Quiescent Current
In Standby mode
A
IVDD
In Power Save mode
-
16
22
In Active mode (VDD < VBUS)
-
550
650
In Active mode (VDD > VBUS)
-
850
1000
2.8
5.0
28
V
-
2.65
2.80
V
-
150
-
mV
VBUS Supply Voltage
VBUS Detection Threshold Voltage
Rising edge
VBUS
VBUS_DET
Hysteresis
VBUS Supply Quiescent Current
In VBUS Power mode
IVBUS
-
-
1.2
mA
In Active mode - Dedicated Charger
-
-
1.2
mA
In Active mode - power MOSFET is off (VBUS < VDD)
-
-
0.5
A
6.8
7.0
7.2
V
-
150
-
mV
1.2
1.8
2.2
A
115
130
145
-
95
-
VDDIO
1.65
-
3.6
VBUS Overvoltage Protection Threshold
Rising edge
VBUS_OVP
Hysteresis
VBUS Overcurrent Protection Threshold
Triggering threshold (at onset of OTP shutoff)
Overtemperature Protection Threshold
Rising threshold
IBUS_OCP
TOTP
Falling threshold
VDDIO Supply Voltage
°C
V
SWITCH
ISET Open Drain Output MOSFET
On resistance (loaded by 3.0 mA current)
Leakage current (when the MOSFET is off at 5.0 V bias voltage)
OUT Pin Discharge MOSFET(6)
On resistance (loaded by 3.0 mA current)
Leakage current (when the MOSFET is off at 5.0 V bias voltage)
Power MOSFET
On resistance (when VBUS = 5.0 V, TA< 50 °C)
RISETB
-
-
100

IISET_OFF
-
-
0.5
A
ROUT_DISC
-
-
100

IOUT_OFF
-
0.5
-
A
-
200
250
RPSW
m
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
7
ELECTRICAL CHARACTERISTICS
STATIC ELECTRICAL CHARACTERISTICS
Table 4. Static Electrical Characteristics (continued)
Characteristics noted under conditions VDD = 3.6 V, VBUS = 5.0 V, VDDIO = 3.0 V, -40 °C  TA  85 °C (see Figure 1), unless
otherwise noted. Typical values noted reflect the approximate parameter means at VDD = 3.6 V and TA = 25 °C under nominal
conditions, unless otherwise noted.
Characteristic
Symbol
Min
Typ
Max
RSPK_ON
-
1.6
3.0
RSPK_ONMCT
-
0.05
0.15
RSPK_ONFLT
-
0.01
0.05
RUSB_ON
-
-
5.0
RUSB_ONMCT
-
0.1
0.5
RUSB_ONFLT
-
0.02
0.1
Unit
SWITCH (CONTINUED)
SPK_L and SPK_R Switches
On resistance (20 Hz to 470 kHz)

Matching between channels
On resistance flatness (from -1.2 V to 1.2 V)
D+ and D- Switches
On resistance (0.1 Hz to 240 MHz)

Matching between channels
On resistance flatness (from 0.0 V to 3.3 V)
RXD and TXD Switches
On resistance

On resistance flatness (from 0.0 V to 3.3V)
MIC Switch
On resistance (at below 2.5 V MIC bias voltage)
On resistance flatness (from 1.8 to 2.3 V)
Pull-down Resistors between SPK_L or SPK_R Pins to GND
RUART_ON
-
-
60
RUART_ONFLT
-
-
5.0
RMIC_ON
-
-
100
RMIC_ONFLT
-
-
5.0
RPD_AUDIO
-
100
-

Signal Voltage Range
SPK_L, SPK_R,
V
D+, D-, RXD, TXD, MIC
PSRR - From VDD (100 mVrms) to DP/DM Pins
20 Hz to 20 kHz with 32/16 load.
Total Harmonic Distortion(7)
20 Hz to 20 kHz with 32/16 load.
k
(7)
-1.5
-
1.5
-0.3
-
3.6
-
-
-60
-
-
0.05
VA_PSRR
dB
THD
Crosstalk between Two Channels
less than 1.0 MHz
VA_CT
Off-Channel Isolation
Less than 1.0 MHz
VA_ISO
%
dB
-
-60
-
-
-80
-
0.5
0.6
0.7
0
-
200
dB
POWER SUPPLY TYPE IDENTIFICATION
Data Source Voltage
Loaded by 0~200 A
VDAT_SRC
Data Source Current
IDAT_SRC
Data Detect Voltage
Low threshold
VDAT_REF
High threshold
Data Sink Current
DM pin is biased between 0.15 V to 3.6 V
V
V
0.3
0.35
0.4
0.8
0.9
1.0
65
100
135
-
8.0
-
-
50
-
A
IDAT_SINK
DP, DM Pin Capacitance
CDP/DM
DP, DM Pin Impedance
All switches are off
RDP/DM
A
pF
M
34825
8
Analog Integrated Circuit Device Data
Freescale Semiconductor
ELECTRICAL CHARACTERISTICS
STATIC ELECTRICAL CHARACTERISTICS
Table 4. Static Electrical Characteristics (continued)
Characteristics noted under conditions VDD = 3.6 V, VBUS = 5.0 V, VDDIO = 3.0 V, -40 °C  TA  85 °C (see Figure 1), unless
otherwise noted. Typical values noted reflect the approximate parameter means at VDD = 3.6 V and TA = 25 °C under nominal
conditions, unless otherwise noted.
Characteristic
Symbol
Min
Typ
Max
Unit
-
2.3
-
1.9
2.0
2.1
30.4
32
33.6
IVCBL
1.0
1.2
1.4
mA
VVCBL_L
-
50
-
mV
ID DETECTION
ID_Float Threshold
Detection threshold
VFLOAT
Pull-up Current Source
When ADC result is 1xxxx
V
A
IID
When ADC result is 0xxxx
ID Shorted to Ground Detection
Detection current
Detection voltage threshold
LOGIC INPUT AND OUTPUT
VDDIO Logic Input Level
Input LOW level
Input HIGH level
Push-pull Logic Output
Output HIGH level (loaded by 1.0 mA current)
Output LOW level (loaded by 4.0 mA current)
Open Drain Logic Output (INT)
Output LOW level (loaded by 4.0 mA current)
VDDIO_IL
-
-
0.5
V
VDDIO_IH
1.5
-
-
V
VOH
0.7VDDIO
-
-
VOL
-
-
0.4
V
VODOL
V
-
-
0.4
VI2C_IL
-0.2
-
0.3VDDIO
V
High Voltage on I C_SDA, I C_SCL Inputs
VI2C_IH
0.7VDDIO
-
VDDIO
V
I2C_SDA
VI2C_OL
-
-
0.4
V
II2C_OL
0
-
4.0
mA
II2C_LEAK
-1.0
-
1.0
A
CI2CIN
-
-
8.0
pF
I2 C
INTERFACE(7)
Low Voltage on I2C_SDA, I2C_SCL Inputs
2
Low Voltage on
Current Load when
2
Output
I2C_SDA
2
Outputs Low Voltage
2
Leakage Current on I C_SDA, I C_SCL Outputs
2
2
Input Capacitance of the I C_SDA, I C_SCL Pins
Notes
6. The OUT pin discharge MOSFET is shown in Figure 15. This MOSFET will be turned on when the power MOSFET is off.
7. These parameters are not tested. They are guaranteed by design.
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
9
ELECTRICAL CHARACTERISTICS
DYNAMIC ELECTRICAL CHARACTERISTICS
DYNAMIC ELECTRICAL CHARACTERISTICS
Table 5. Dynamic Electrical Characteristics
Characteristics noted under conditions VDD = 3.6 V, VBUS = 5.0 V, VDDIO = 3.0 V, -40°C  TA  85°C (see Figure 1), unless
otherwise noted. Typical values noted reflect the approximate parameter means at VDD = 3.6 V and TA = 25°C under nominal
conditions, unless otherwise noted.
Characteristic
Symbol
Min
Typ
Max
Unit
tD2
7.0
8.5
10.2
tVDDDGT_F
1.7
2.5
3.5
tVBUS_DET
3.5
4.5
5.7
tOVPD
-
-
2.0
tOVPDGT_F
-
25
-
MOSFET turning off speed when OTP occurs(10)
tOTP_TO
-
-
0.5
A/s
Deglitch time
tOTP_DGT
-
15
-
s
fOSC
85
100
112
kHz
POWER ON AND OFF DELAY
VDD Power-On-Reset Timing
VDD rising deglitch time
ms
VDD falling deglitch time
VBUS Detection Deglitch Time (for Both Rising and Falling
Edges)(10)
s
VBUS Overvoltage Protection
Protection delay(8)(10)
Falling edge deglitch time(9)
ms
VBUS Overtemperature Protection
OSCILLATOR
Oscillation Frequency
SWITCHING DELAY
ID Detection Delay Time after VBUS Applied (Default Value is TD = 0100)
TD = 0000
tD
ms
-
100
-
TD = 0001
-
200
-
TD = 0010
-
300
-
-
400
-
TD = 0011
TD = 0100
-
500
-
......
......
......
-
1600
-
tID_FLOAT
-
20
-
ms
tVCBL
-
20
-
ms
tCONV
-
1.0
-
ms
tRMTCON_DG
-
20
-
ms
tRSTDVC
-
10
-
s
tVDDIODGT_R
660
875
1130
tVDDIODGT_F
105
125
150
tRSTVDDIO
150
-
-
......
TD = 1111
ID DETECTION
ID Float Detection Deglitch Time
ID Shorted to Ground Detection Time (The Detection Current Source On Time)
ADC
ADC Conversion Time
REMOTE CONTROL
Key Press Comparator Debounce Time
RESET TIMING
Device Reset Time
VDDIO Logic Input Timing
Rising edge deglitch time
Falling edge deglitch time
VDDIO Reset Timing
VDDIO reset pulse width
s
s
34825
10
Analog Integrated Circuit Device Data
Freescale Semiconductor
ELECTRICAL CHARACTERISTICS
DYNAMIC ELECTRICAL CHARACTERISTICS
Table 5. Dynamic Electrical Characteristics
Characteristics noted under conditions VDD = 3.6 V, VBUS = 5.0 V, VDDIO = 3.0 V, -40°C  TA  85°C (see Figure 1), unless
otherwise noted. Typical values noted reflect the approximate parameter means at VDD = 3.6 V and TA = 25°C under nominal
conditions, unless otherwise noted.
Characteristic
Symbol
Min
Typ
Max
I2C reset pulse width
tRSTI2C
13.5
-
-
I2C_SDA/I2C_SCL concurrent low time without causing a reset
tNRSTI2C
-
-
8.8
SCL Clock Frequency
fSCL
-
-
400
kHz
Bus Free Time between a STOP and START Condition
tBUF
1.3
-
-
s
tHD:STA
0.6
-
-
s
Low Period of SCL Clock
tLOW
1.3
-
-
s
High Period of SCL Clock
tHIGH
0.6
-
-
s
Setup Time for a Repeated START condition
tSU:STA
0.6
-
-
s
Data Hold Time
tHD:DAT
0.0
-
-
s
Data Setup Time
tSU:DAT
100
-
-
ns
Rising Time of Both SDA and SCL Signals
tR
20+0.1CB
-
-
ns
Falling Time of Both SDA and SCL Signals
tF
20+0.1CB
-
-
ns
tSU:STO
0.6
-
-
s
tDGT
55
-
300
ns
I2C Reset Timing
Unit
ms
I2C INTERFACE(10)
Hold Time Repeated START Condition
Setup Time for STOP Condition
Input Deglitch Time (for Both Rising and Falling Edges)
Notes
8. The protection delay is defined as the interval between VBUS voltage rising above the OVP rising threshold, and the OUT pin voltage
dropping below the OVP rising threshold voltage for a VBUS ramp rate of >1.0 V/s.
9. The OVP deglitch timer is only for the falling edge threshold.
10. These parameters are not tested. They are guaranteed by design.
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
11
ELECTRICAL CHARACTERISTICS
ELECTRICAL PERFORMANCE CURVES
2.2
Temperature =85°C
2.0
1.8
Temperature =25°C
1.6
1.4
-1.5
Temperature = -40°C
-1.0
-0.5
0.0
0.5
1.0
1.5
MIC Switch On-Resistance ( )
SPK Switch On-Resistance ( )
ELECTRICAL PERFORMANCE CURVES
90
Temperature = 85°C
80
70
Temperature = 25°C
60
50
40
1.8
Temperature = -40°C
1.9
Input Voltage ( V)
9.6
VDD Supply Current ( A)
4.5
Temperature = 85°C
4.0
3.5
Temperature = 25°C
3.0
Temperature = -40°C
2.5
2.0
0.0
0.5
1.0 1.5 2.0 2.5
Input Voltage ( V)
3.0
3.5
Figure 5. USB Switch On Resistance vs Input Voltage
UART Switch On-Resistance ( )
2.3
Figure 7. MIC Switch On Resistance vs Input Voltage
9.4
9.2
9.0
8.8
8.6
2.5
3.0
3.5 4.0 4.5
VDD Voltage ( V)
5.0
5.5
Figure 8. VDD Supply Current vs Supply Voltage in
Standby Mode
45
40
11
Temperature = 85°C
35
Temperature = 25°C
30
25
20
0.0
Temperature = -40°C
VDD Current ( A)
USB Switch On-Resistance ( )
Figure 4. SPK Switch On Resistance vs Input Voltage
2.0
2.1
2.2
Input Voltage ( V)
10
9
8
7
0.5
1.0 1.5 2.0 2.5
Input Voltage ( V)
3.0
3.5
Figure 6. UART Switch On Resistance vs Input Voltage
-40
-20
0
20
40
60
Temperature ( °C)
80
Figure 9. VDD Supply Current vs Temperature In
Standby Mode
34825
12
Analog Integrated Circuit Device Data
Freescale Semiconductor
900
9.0
880
OUT Voltage (V)
VBUS Supply Current ( A)
ELECTRICAL CHARACTERISTICS
ELECTRICAL PERFORMANCE CURVES
860
840
820
800
780
760
-40
7.5
6.0
4.5
3.0
1.5
-20
0
20
40
60
80
Temperature ( °C)
Figure 10. VBUS Supply Current vs Temperature In
VBUS Power Mode
0.0
0.0
1.5
3.0
4.5
6.0
VBUS Voltage ( V)
7.5
9.0
Figure 11. OUT Voltage vs VBUS Voltage
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
13
FUNCTIONAL DESCRIPTION
INTRODUCTION
FUNCTIONAL DESCRIPTION
INTRODUCTION
The 34825 is designed to support cell phones that adopt
the micro or mini-USB connector as the sole wired interface
between the cell phone and external accessories. Using the
micro-USB connector for charging and USB data
communication is required by the OMTP standard for the
UCS. The 34825 further extends the micro-USB connector to
support other accessories to eliminate all other mechanical
connectors in a cell phone. The supported accessories
include various audio headsets, UART connection, R/D test
cables for firmware downloading, and other user defined
accessories, in addition to the chargers defined in the Battery
Charging Specification, Revision 1.0, from the USB
Implementer’s Forum and the CEA-936-A USB Carkit
Specification, from the Consumer Electronics Association
(CEA). The supported chargers are listed in Table 8.
The 34825 offers two mechanisms to assist the
identification of the accessory. The ID detection mechanism
allows the cell phone to measure the ID resistor value
between the ID pin and the ground with a 5-bit ADC. The
VBUS detection mechanism allows the cell phone to find out
the connection status between the D+ and D- pins. Together,
the exact accessory can be determined. A detection flow is
initiated by a change in the VBUS pin voltage or by a change
in the ID pin floating status. Detaching the accessory from the
micro or mini-USB connector causes the VBUS voltage or/
and the ID resistance to change. The identification flow will be
initiated to confirm if an accessory is still connected. The host
can also initiate the identification flow by resetting an ACTIVE
bit in the register from 1 to 0.
Upon the completion of the identification flow, an interrupt
signal is sent to the host IC, so the host IC can take further
actions. The 34825 contains switches that the host IC can
control via an I2C interface. Based on the accessory, the host
IC can configure the switch connections in the 34825, so that
the signal paths for the USB communication, or the UART
communication, or audio accessories can be established
between the micro or mini-USB connector pins and the
system ICs. If the accessory is a power supply, the supplied
voltage is switched to the Li-ion battery charging function in
the cell phone via an internal power MOSFET.
The host IC controls the 34825 via the I2C serial bus. The
register map in the 34825 contains status information of the
device and the control bits that the host IC can access to
control the 34825.
FUNCTIONAL PIN DESCRIPTION
SPEAKER RIGHT CHANNEL (SPK_R)
Right channel of the baseband speaker output.
SPEAKER LEFT CHANNEL (SPK_L)
Left channel of the baseband speaker output.
MICROPHONE OUTPUT (MIC)
Microphone output to the baseband.
D+ OF THE USB TRANSCEIVER (D+)
D+ line of the USB transceiver.
D- OF THE USB TRANSCEIVER (D-)
D- line of the USB transceiver.
UART RECEIVER (RXD)
Receiver line of the UART.
UART TRANSMITTER (TXD)
Transmitter line of the UART.
NO CONNECT (NC)
These pins are not used in application. Freescale
recommends that these pins be floated
IO POWER SUPPLY (VDDIO)
Power supply input for the logic IO interface. Generally the
IO power supply voltage should be the same as the IO
voltage used in the cell phone system. VDDIO is also one of
the hardware reset input sources. A falling edge at this pin will
reset the 34825. See Reset for more information.
POWER SUPPLY (VDD)
Power supply input. Bypass to ground with a 1.0 F
capacitor.
INTERRUPT OUTPUT (INT)
Active low open-drain output. The INT pin sends an
interrupt signal to the host IC when an interrupt event
happens. The INT output returns to high voltage once all
interrupt bits are read.
DATA LINE OF THE I2C INTERFACE (I2C_SDA)
Data line of the I2C interface.
I2C CLOCK (I2C_SCL)
Clock line of the I2C interface. The I2C_SCL input together
with the I2C_SDA input forms one of the hardware reset input
sources.
34825
14
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DESCRIPTION
FUNCTIONAL PIN DESCRIPTION
POWER OUTPUT (OUT)
Output of the power MOSFET in the 34825. This pin is
connected to a charger input. Bypass to ground with a 1.0 F
capacitor.
CHARGE CURRENT SETTING (ISET)
D- OF THE USB CONNECTOR (DM)
D- line of the mini or micro-USB connector.
D+ OF THE USB CONNECTOR (DP)
D+ line of the mini or micro-USB connector.
Open-drain output to set the charge current according to
the power supply current capability.
ID OF THE USB CONNECTOR (ID)
VBUS POWER SUPPLY (VBUS)
GROUND (GND)
USB VBUS input. Bypass this pin to ground with a less
than 10 nF capacitor. When the accessory is an audio kit, this
pin is the microphone input to the 34825.
ID pin of the mini or micro-USB connector.
Ground.
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
15
FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
I2C
Interface
Logic
Output
Internal
Power
Supplies
Switch
Array
Logic &
State
Machine
VBUS
Detection
ID ADC
ID
Detection
Figure 12. 34825 Functional Internal Block Diagram
INTERNAL POWER SUPPLIES
SWITCH ARRAY
This block contains the bias power supplies to the internal
circuits. The inputs to this block include VBUS, VDD and
VDDIO.
The switch array consists of analog switches for UART,
USB, audio signal switching and one high-voltage power
MOSFET for power switching.
LOGIC AND STATE MACHINE
VBUS DETECTION
This block includes the state machine for accessory
detection and identification, the register map, and other logic
circuits.
This block detects whether the power supply at VBUS pin
is present or removed.
I2C INTERFACE
ID DETECTION
The I2C interface block has the circuit for the I2C
communication that a master device can use to access the
registers in the 34825. The 34825 is a slave device.
This block contains a circuit to detect whether an ID resistor
is connected to the ID pin or not.
LOGIC OUTPUT
An internal 5-bit ADC measures the resistance at the ID
pin. The result is stored in the ADC Result register and sent
to the Logic and State Machine block to determine what
accessory is attached.
The logic output includes two open-drain logic output
signals, INT and ISET.
ID ADC
34825
16
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
The 34825 has five operational modes: Power Down
mode, VBUS Power mode, Standby mode, Active mode, and
Power Save mode. The mode transition diagram is given in
Figure 13.
VBUS power down
Power
Down
VBUS power up
VBUS
Power
VDD > VVDDPOR
VDD < VVDDPOR
VDD > VVDDPOR
VDD < VVDDPOR
I2C resets ACTIVE bit or
detachment of accessory
Standby
Active
ID det or VBUS det
2
I C or detection
of no activity
I2C or detection
of the activity
Detachment
of accessory
Power
Save
Figure 13. Mode Transition Diagram
POWER DOWN MODE
ACTIVE MODE
The Power Down mode is when neither the VDD pin nor
the VBUS pin is powered. In this mode, the IC does not
respond to any accessory attachment except for a power
supply. When an external power supply is plugged into the
mini or micro-USB connector, the 34825 enters the VBUS
Power mode.
The Active mode starts when an accessory is plugged into
the mini or micro-USB connector while the VDD pin is
powered. The 34825 identifies the accessory and interrupts
the host IC for further actions. Different functions will be
enabled according to the identification result, so the
quiescent current in Active mode is dependent on the type of
accessories.
The operational mode can be changed from Active to
Standby either by an accessory detachment or by resetting
the ACTIVE bit to 0 through an I2C programming operation.
VBUS POWER MODE
The 34825 enters the VBUS Power mode when the VBUS
pin is powered but the VDD pin is not. In the VBUS Power
mode, the internal power MOSFET is turned on to power the
charging function in the cell phone. The ISET pin outputs
high-impedance in this mode.
STANDBY MODE
The Standby mode is when the VDD voltage is higher than
the POR (Power-On-Reset) threshold and no accessory is
attached. In this mode, only the ID detection circuit, the I2C
interface, and the internal registers are powered in order to
minimize the quiescent current from the VDD pin. The ID
detection circuit samples the status of the ID line every
50 ms.
If detecting an attachment of an accessory, the 34825
moves to the Active mode for further accessory identification.
POWER SAVE MODE
The Power Save mode can be enabled only for
accessories with a remote controller (refer to Table 22). The
34825 enters into the Power Save mode to minimize the
operating current while such an accessory is attached, but
not in operation. For example, if the cell phone is not in an
audio playback mode when a headset is attached, the host IC
can force the 34825 to the Power Save mode via the I2C
programming. The 34825 can also automatically enter into
the Power Save mode when no activity is detected on the
SPK_R or SPK_L pins in 10 seconds. The VDD current in the
Power Save mode is slightly higher than the current in the
Standby mode.
The 34825 can exit the Power Save mode by an I2C
programming or will exit the mode automatically when
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
17
FUNCTIONAL DEVICE OPERATION
POWER-UP
detecting audio signal activities or an accessory detachment.
If the transition is caused by an accessory detachment, the
34825 moves from the Power Save mode to the Standby
mode directly. Otherwise, it moves to the Active mode, and
the configuration of the IC resumes to the same configuration
before entering the Power Save mode.
DEVICE MODE REGISTER
The PSAVE bit, ACTIVE bit and RST bit in the Device
Mode register (refer to Table 10) hold the information of the
device operational mode. The RST bit, which is of R/C (read
and clear) type, indicates whether a reset has occurred. The
RST bit is set when a reset occurs (refer to Reset for more
information). The RST bit is cleared when read by an I2C
access. The ACTIVE bit and the PSAVE bit together indicate
the device mode by the relationship shown in Table 6. When
the device is in the VBUS Power mode, the registers are not
powered up.
The ACTIVE bit is a R/W (read and write) bit, it can be
written by an I2C operation. When the host IC writes ‘0’ to the
ACTIVE bit, the device will be forced to the Standby mode. If
an accessory is attached when the ACITVE is set to 0, the
accessory identification flow shown in Figure 14 will be restarted.
The PSAVE bit is also a R/W bit. When the 34825 is
configured to the Auto Power-save mode (AutoPSAVE bit is
set to 1), the PSAVE bit indicates whether the 34825 is in the
Power Save mode or not. When the 34825 is configured to
the Manual Power-save mode (AutoPSAVE bit set to 0), the
host IC can writes ‘1’ to the PSAVE bit to force the 34825 into
the Power Save mode when an Audio R/C accessory is
attached. For all other accessories attachment, the 34825
does not enter the Power Save mode even the PSAVE bit is
set to 1.
Table 6. The Device Modes vs. the Register Bits
PSAVE
ACTIVE
MODE
0
0
Standby
0
1
Active
1
1
Power Save
1
0
Undefined
POWER-UP
The 34825 has four possible power-up scenarios
depending on which of the VDD pin and the VBUS pin is
powered up first. The four scenarios correspond to the
following four mode transitions.
1. From Power Down to VBUS Power: the VBUS pin is
powered up when VDD < VVDDPOR (VDD POR
threshold)
2. From VBUS Power to Standby: VBUS is already
powered when the VDD voltage rises above its POR
threshold
3. From Power Down to Standby: the VDD pin is
powered up when VBUS < VVBUSPOR (VBUS POR
threshold)
4. From Standby to Active: the VDD pin is already
powered when the VBUS voltage rises above its POR
threshold
SCENARIO 1: VDD = 0 V AND VBUS IS POWERED
UP (POWER DOWN MODE TO VBUS POWER
MODE TRANSITION)
If the VDD pin is not powered but the VBUS is powered up
within a voltage range between the POR threshold and the
OVP (overvoltage protection) threshold, the internal power
MOSFET is softly turned on. The IC is in the VBUS Power
mode.
In this VBUS Power mode, the ISET outputs highimpedance and all registers are in the reset state. The power
MOSFET remains on unless it is disabled by the overvoltage
protection or the overtemperature protection block.
SCENARIO 2: VBUS = HIGH AND VDD IS
POWERED UP (VBUS POWER MODE TO STANDBY
MODE TRANSITION)
If the VBUS pin is already powered when the VDD pin is
powered up, the device moves from the VBUS Power mode
to the Standby mode and then quickly moves to the
identification flow of the Active mode to identify the
accessory, as shown in Figure 14.
After the VDD pin is powered up, the 34825 starts up the
internal supplies. The POR resets all register bits. The power
MOSFET remains on during the reset process.
SCENARIO 3: VBUS = 0 V AND VDD IS POWERED
UP (POWER DOWN MODE TO STANDBY MODE
TRANSITION)
If no accessory is plugged into the micro or mini-USB
connector when VDD is powered up, the 34825 moves from
the Power Down mode to the Standby mode. The internal
supplies are started up first, and then the whole chip is reset
and is ready to accept accessories. Then when an accessory
is attached, the 34825 enters the Active mode. The power
MOSFET is off in this case since VBUS = 0 V.
SCENARIO 4: VDD = HIGH AND VBUS IS
POWERED UP (STANDBY TO ACTIVE MODE
TRANSITION)
This is a normal VBUS detection case as shown in
Figure 14. More description can be found in Power Supply
Type Identification.
34825
18
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DEVICE OPERATION
ACCESSORY IDENTIFICATION
ACCESSORY IDENTIFICATION
Accessories are categorized into two groups. Powered
accessories are accessories that supply power to the VBUS
pin while non-powered accessories do not. When the
accessory is a powered one, the VBUS detection mechanism
will check the connection between the D+ and the D- pins as
part of the power supply type identification (PSTI). A powered
accessory may or may not have an ID resistor. A nonpowered accessory must have an ID resistor for the
identification purpose.
Accessories that have an ID resistor are grouped into
three types, as listed in Table 22.
1. Test Accessories. Such accessories include two USB
test cables that are powered accessories, and two
UART test cables that are non-powered accessories. A
test accessory has an ID resistor and four ID resistor
values are reserved for them (see Table 22 for the ID
resistor assignment). The USB or the UART switches
in the IC will be turned on automatically when a test
accessory is attached.
2. Accessories with a remote controller. Two accessories
are offered to support remote control (RC) keys. The ID
resistor values are 619 k and 1.0 M respectively, as
given in Table 22. Such accessories are non-powered
accessories. The 34825 monitors the ID pin
continuously for key pressing when such an accessory
is connected. 13 ID resistors are assigned to the
remote control keys, as listed in Table 22.
3. Other accessories. The remaining ID resistor values
are reserved for users to assign to their own
accessories.
The identification flow chart is shown in Figure 14. In the
Standby mode, the 34825 monitors both the ID pin and the
VBUS pin simultaneously. If an accessory is detected, the
identification state machine will find out in parallel the ID
resistor value and the type of the power supply (if a powered
accessory is attached). When the 34825 is in the Active mode
with the ACTIVE bit = 1, the host IC can force the ACTIVE bit
to 0 via the I2C bus to initiate the identification state machine.
The details on the identification flow for the VBUSdetection mechanism and the ID detection mechanism are
described as following.
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
19
FUNCTIONAL DEVICE OPERATION
ACCESSORY IDENTIFICATION
VBUS=0V
No
ACTIVE = 0
ID Float
VBUS
Applied?
ID Float?
Yes
Set
DETACH bit
Yes
No
Set
VBUS_DET bit
Clear
ID_FLOAT bit
Set
ID_FLOAT bit
Yes
Set
ADC RESULT
Set
ID_GND bit
Yes
ID shorted
to GND?
Yes
No
No
ID Float?
ADC =
00000?
No
Yes
Delay
TD time
Yes
Key
Released?
VBUS_DET
=1?
No
DP->DM
SHORT?
ADC =
Key Value?
No
Yes
Yes
Key Released
within 1.5s?
No
Set
ATTACH bit
No
Yes
ID_FLOAT
=1?
No
No
Yes
No
ADC =
1000x?
Yes
Yes
DM->DP
SHORT?
Turn on
USB switches
ADC =
0111x?
No
Yes
Turn on
UART
switches
No
Set DP/DM
_SHORT bit
Set
USB_CHG bit
Set
ATTACH bit
Set
ACTIVE bit
Figure 14. Detailed Accessory Identification Flow Diagram
ID DETECTION
The ID detection relies on the resistance between the ID
pin and the ground (RID) inside the accessory for the
accessory detection and recognition. The nominal ID
resistance that the 34825 supports is listed in Table 7 as well
as in Table 22. The 34825 offers a 5-bit ADC for the
resistance recognition and the corresponding ADC results vs.
the RID are also listed in Table 7. The resistors are required
to have 1% or better accuracy for the ADC to recognize
successfully.
A comparator monitors the ID pin for attachment and
detachment detection. When no accessory is attached, the ID
pin is floating. An ID_FLOAT bit in the Status register stays in
the value of 1. When a resistor less than or equal to 1.0 M
is connected between the ID line and the ground, the
ID_FLOAT bit changes to 0. When the resistor is removed,
ID_FLOAT bit returns to 1. A falling-edge of the ID_FLOAT bit
represents the attachment of the accessory and the ADC is
enabled to measure the ID resistance. The ADC Result
register has the identification result of the RID, as given in
Table 7. A rising edge of the ID_FLOAT bit represents the
detachment of the accessory.
34825
20
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DEVICE OPERATION
ACCESSORY IDENTIFICATION
The ADC results are broken into two groups. The values
between ‘00001’ to ‘01101’ are assigned to 13 remote-control
keys for the two accessories that support remote controllers,
as listed in Table 22. The rest of the ADC results are
assigned to various accessories. If the ADC result is one of
the remote control key values in the identification flow, it is
possible that the remote control key is stuck when the
accessory is attached.
A special Stuck Key Identification flow is designed to
resolve such an issue. As shown in the Figure 14, if the stuck
key is recognized but is released within 1.5s, the identification
flow will return to re-detect the ID line; Otherwise, the
ATTACH bit will be set and the ADC Result register has the
key result. After the key is released, the 34825 will detect the
ID resistance value again. If the accessory is still connected,
the ATTACH bit is set again and the ADC result has the ID
resistor value of the accessory.
When the ADC result is 00000, the resistance between the
ID pin and the ground is less than 1.90 k. The ID_GND bit
in the Status register indicates whether the ID pin is shorted
to ground or not. If the ID pin is shorted to ground with less
than 30 of resistance, the ID_GND pin is set to “1”.
Table 7. ADC Output vs. Resistor Values (Unit: k)
ADC Result
RID (k)
ADC Result
RID (k)
ADC Result
RID (k)
ADC Result
RID (k)
00000
(1)
01000
10.03
10000
40.2
11000
255
00001
2.00
01001
12.03
10001
49.9
11001
301
00010
2.604
01010
14.46
10010
64.9
11010
365
00011
3.208
01011
17.26
10011
80.6
11011
442
00100
4.014
01100
20.5
10100
102
11100
523
00101
4.820
01101
24.07
10101
121
11101
619
00110
6.03
01110
28.7
10110
150
11110
1000
00111
8.03
01111
34.0
10111
200
11111
(2)
Notes
1. If the ID resistance is below 1.90 k (nominal value), the ADC result is set to 00000.
2. If the ID line is floating, the ADC result is set to 11111
POWER SUPPLY TYPE IDENTIFICATION
The 34825 supports various standard power supplies for
charging the battery. The power supplies supported include
those that are user defined, and the ones defined in the
Battery Charging Specification, Revision 1.0, from the USB
Implementer’s Forum and the CEA-936-A USB Carkit
Specification, from the Consumer Electronics Association.
The five types of power supplies specified in the afore
mentioned two specification documents are listed in Table 8.
The Power Supply Type Identification (PSTI) function is
offered to assist the identification of the power supply type.
The PSTI state machine checks the connection status
between the DP and the DM pins. The state machine starts
when the VBUS pin voltage rises above the VBUS detection
threshold, which is indicated with an VBUS_DET bit in the
status register. The state machine will find out if the DP and
DM pins are shorted, indicated with the DP/DM_SHORT bit,
or the connection has the characteristics of a USB charger,
indicated with the USB_CHG bit. Together with the ID
detection result, the power supply type can be determined.
The conditions for reaching the conclusion of the five
supported power supplies are listed in Table 8.
Table 8. Power Supply Type vs. Detection Result
Item #
VBUS_DET
DP/DM_SHORT
USB_CHG
ID_FLOAT
ADC Result
Accessory Type
1
1
0
0
1
11111
Standard USB Port
2
1
0
1
1
11111
USB Charger
3
1
1
0
1
11111
Dedicated Charger
4
1
1
0
0
10111
Carkit Charger Type 1
5
1
1
0
0
11011
Carkit Charger Type 2
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
21
FUNCTIONAL DEVICE OPERATION
OPERATION AFTER IDENTIFICATION
OPERATION AFTER IDENTIFICATION
The operation after the identification is dependent on the
VDDIO voltage. The VDD voltage has to be higher than its
POR threshold for the 34825 to perform the identification
state machine. Once completed, the identification results are
stored in the Status and the ADC Result registers and the
ATTACH bit is set. If the VDDIO is not powered, the interrupt
signal from the INT pin cannot be sent because the INT pin is
normally pulled up to the VDDIO. The host cannot access the
34825 either via the I2C bus. Hence, no communication will
occur between the 34825 and the host IC when the VDDIO is
not powered. The INT signal will send an interrupt signal if the
VDDIO is powered and the ATTACH bit is not masked by the
ATTACH_m bit (refer to Interrupt on page 27 for more
details). If the ATTACH bit is masked while the VDDIO is
powered, the interrupt signal will not be sent but the host IC
can still access the register map via the I2C bus. Once the
host IC accesses the 34825 register map and determines the
accessory type, it can manage the analog switches and other
signals in the 34825 by programming the S/W Control 1 and
S/W Control 2 registers.
The switches are open by default except if the attached
accessory is one of the four test cables listed in Table 22.
More descriptions on the analog switches and the operation
of the 34825 are given in the following sections.
ANALOG SWITCHES
SIGNAL SWITCH ARRAY
The 34825 offers an array of analog switches for signal
switching, as shown in Figure 15. Two pairs of switches (USB
and UART) are for switching the UART and USB signals to
the micro or mini-USB connector. Stereo audio signals can
be switched from the SPK_L and the SPK_R inputs to the DP
and the DM pins that are wired to the USB connector. Both
the SPK_L and the SPK_R inputs are capable of passing
RXD
signals of +/-1.5 V, referencing to the GND pin voltage. The
SPK_L and the SPK_R pins are pulled down to ground via a
100 k resistor respectively, as shown in Figure 15. A
microphone switch connects the MIC pin to the VBUS pin.
All switches are controlled by bits in the S/W Control 1 and
2 registers except when the accessory attached is a test
cable.
DP
SW1
TXD
DM
SW2
SW3
D+
SW6
DSW4
SPK_R
SW7
SPK_L
SW5
MIC
ISET
SW9
Gate
Drive
VBUS
SW8
OUT
SW10
Figure 15. Analog and Digital Switches
34825
22
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DEVICE OPERATION
OPERATION AFTER IDENTIFICATION
POWER MOSFET
The SW8 in Figure 15 is a power MOSFET that controls
the power flow from the VBUS input to the OUT pin. The
power MOSFET serves two purposes. For the Audio
accessory with microphone, the power MOSFET isolates the
VBUS pin from both the input decoupling capacitor and the
input quiescent current of the charger IC connected to the
OUT pin, so that the microphone signal can be connected to
the VBUS pin without any interference from the OUT pin. The
power MOSFET is also used as the input overvoltage
protection (OVP) or overcurrent protection (OCP) switch for
other components in the cell phone, such as the charger IC,
to allow a low voltage rated charger IC to be used for cost
reduction.
The power MOSFET is guaranteed to be turned on in
VBUS power mode even when the VDD voltage is below
VVDDPOR threshold, to ensure that the cell phone battery can
be charged when the battery is fully discharged.
PROTECTION
OVERVOLTAGE PROTECTION (OVP)
The VBUS line is capable of withstanding a 28 V voltage.
The 34825 protects the cell phone by turning off the internal
power MOSFET when the VBUS voltage is higher than the
OVP threshold. In this case, the 34825 turns off the power
MOSFET within 1.0 s after the input voltage exceeds the
OVP threshold, and the OVP_EN bit in the Interrupt register
is set to interrupt the host IC. When the OVP event is cleared,
the OVP_OTP_DIS bit in the Interrupt register is set to inform
the host IC.
OVERCURRENT PROTECTION (OCP) AND
OVERTEMPERATURE PROTECTION (OTP)
If the current flowing through the power MOSFET exceeds
the specified OCP limit, the 34825 will operate in CC
(constant current) mode, regulating the output current at the
OCP limit. If the OCP condition persists, the IC temperature
will rise, eventually reaching the overtemperature protection
(OTP) limit. The 34825 then turns off the power MOSFET and
sets the OTP_EN interrupt bit in the Interrupt register to
inform the host IC. The power MOSFET is turned on again
when the IC temperature falls below the OTP falling
temperature threshold, and the OVP_OTP_DIS bit is set. If
the above case happens repeatedly seven times, the power
MOSFET will be permanently turned off until the accessory is
detached or the IC is reset.
The power MOSFET is turned off with a limited speed
under the OTP case to prevent a high overshoot voltage at
the VBUS pin.
OPERATION WITH ACCESSORIES
AUDIO ACCESSORY SUPPORTING REMOTE
CONTROLLER (R/C ACCESSORY)
Two ID resistors are designated for accessories with a
remote controller, as listed in Table 22. A typical accessory
with a remote controller is an audio headset that has a stereo
speaker, a micro phone, and a remote controller, as shown in
Figure 16. The five pins in the mini or micro-USB connector
are assigned in Figure 16. If some components are not
included in the accessory, the corresponding pins should be
left floating. For example, if the microphone is not included in
the stereo headset, VBUS pin should be left floating in the
headset.
The timing of the key pressing is shown in Figure 17. If a
key is pressed for a time less than 20 ms, the 34825 ignores
this key press. If the key is still pressed after 20 ms, 34825
starts a timer to count the time during which the key is
pressed. There are three kinds of key press conditions
according to the pressing time: error key press, short key
press, and long key press.
1. Error key press: if the key pressing time is less than
TKP, The 34825 ignores this key press.
2. Short key press: if the key pressing time is between
TKP and TLKP, the KP bit is set to inform the host IC.
The ADC result holds the key value. The INT outputs
low impedance when the key is released and returns to
a high -mpedance, due to the clearance of the KP bit
when the interrupt register is read.
3. Long key press: if the key pressing time is longer than
TLKP, the long key press bit LKP in the Interrupt register
is set to inform the host IC. The host IC needs to
respond to the key press immediately. The ADC result
holds the key value. When the key is released, the long
key release bit LKR in the Interrupt register is set to
interrupt the host IC again. The ADC Result register
still has the key value.
When such a accessory is attached, the 34825 can either
be forced into the Power Save mode or automatically enter
into the Power Save mode. This is controlled by the
AutoPSAVE bit in the Control register.
When AutoPSAVE = 1, if no activity is detected at the
SPK_L and SPK_R pins in 10 seconds, the 34825 enters the
Power Save mode automatically to minimize the quiescent
current. Upon detecting the activity in audio signal switches,
the 34825 returns to the Active mode. When AutoPSAVE = 0,
the host IC can control the mode of 34825 manually by
setting the PSAVE bit in the Device Mode register via I2C.
In the Power Save mode, the key pressing is monitored as
well.
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
23
FUNCTIONAL DEVICE OPERATION
OPERATION AFTER IDENTIFICATION
VBUS
AUDIO
ACCESSORY
D+
MIC
Audio_R
DAudio_L
ID
R1
R2
RN-1
R3
…...
/
SEND/END
GND
RN
HOLD
Figure 16. Audio Accessory with Remote Control and Microphone
TKP
20 ms
Key Press
TLKP
20 ms
20 ms
KP
INT
Interrupt Register read
LKP
LKR
INT
Interrupt Register read
ADC Time
Interrupt Register read
Figure 17. The Remote Control Key Pressing Timing
TEST ACCESSORY
The Test Accessories listed in Table 22 are special USB
cables and UART cables for test and R/D purpose. It has an
ID resistance to differentiate it from a regular USB cable or
UART cable. The test accessory has four ID resistance
values to distinguish the test cable type. The detection result
turns on or off the USB switches, UART switches, and the
power MOSFET automatically, as shown in the Table 9.
Table 9. Switch Status vs. Test Cables
Accessory Type
ADC Result
Auto-ON Switches
Power MOSFET
UART test cable type 1
01110
UART Switches
OFF
UART test cable type 2
01111
UART Switches
OFF
USB test cable type 1
10000
USB Switches
ON
USB test cable type 2
10001
USB Switches
ON
Other accessories
others
No auto-on Switches No auto-on Switches
34825
24
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DEVICE OPERATION
OPERATION AFTER IDENTIFICATION
USB HOST (PC OR HUB)
When the attached accessory is a USB host or hub, the ID
pin is floating. The power MOSFET is turned on to allow the
charger to charge the battery. The ISET outputs default high
impedance to limit the charging current to a lower level. The
host IC can turn on the D+ and D- switches and then pull the
D+ signal to high to start the USB attaching sequence.
USB CHARGER OR DEDICATED CHARGER
When the attached accessory is a USB Charger or a
Dedicated Charger, the 34825 turns on the power MOSFET
to allow the charger to start. The host IC can set the ISET
outputs low impedance to allow a higher charge current.
5-WIRE CARKIT CHARGER (TYPE 1 OR TYPE 2)
A 5-wire carkit charger is a charger specified in the CEA936-A USB Carkit Specification. The 5-wire carkit charger
outputs 5.0 V to the VBUS pin, has the D+ and D- pins
shorted internally, and has an ID resistor. The ID resistor has
a value of either 200 k or 440 k to distinguish the current
capability of the charger. Refer to the CEA-936-A USB Carkit
Specification for more information.
When the attached accessory is a 5-wire carkit charger,
the 34825 turns on the power MOSFET to allow the Li-ion
battery charging function to start. The host can set the ISET
outputting high-impedance or low impedance to choose the
charge current.
RESERVED ACCESSORY
The users can assign the reserved ID resistor values listed
in Table 22 to their user specific accessories. When a user
specific accessory is attached, the identification flow will
identify the ID resistance and as well as the power supply
type in case of a powered accessory. The ADC Result
register and the Status register contain the information of the
RID value and the power supply type. The baseband can read
these registers to distinguish the type of the accessory for
further actions.
DETACHING DETECTION
When either the VBUS voltage drops below the VBUS
power detection threshold or the ID resistor is removed, a
detaching detection flow starts. Figure 18 shows the detailed
detection flow. When the DETACH bit is set, the INT outputs
low voltage to inform the host IC. At the end of the detaching
detection flow, the ACTIVE bit is cleared and the 34825
enters the Standby mode. A new identification flow will start
if either the VBUS voltage is above its POR threshold or the
ID resistor is connected.
RID
Connected
VBUS=5V
No
VBUS
Removed
Yes
Clear
VBUS_DET bit
No
ID Float
Yes
Set
ID_FLOAT bit
Clear
ATTACH bit
Set
DETACH bit
Clear
ACTIVE bit
Figure 18. The Detachment Detection Flow
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
25
FUNCTIONAL DEVICE OPERATION
LOGIC CONTROL FEATURES
LOGIC CONTROL FEATURES
RESET
HARDWARE RESET
The 34825 has three sources for hardware resetting the
IC. As the Figure 19 shows, the sources include the PowerOn-Reset caused by the rising VDD, a hardware reset caused
by the VDDIO input and a hardware reset using the I2C bus
lines. The Power-On-Reset is described earlier. The reset
caused by the VDDIO input or by the I2C bus lines belongs to
system resets.
The hardware reset condition using the I2C signals is
shown in Figure 20. When both the I2C_SCL and the
I2C_SDA have a negative pulse with time of tRSTI2C, a
hardware reset is generated. The result of the reset is same
as a Power-On-Reset.
The operating waveforms of the hardware reset using the
VDDIO pin are shown in Figure 21. The VDDIO detection has
a deglitch-time tVDDIODGT_F. A glitch on the VDDIO with
I2C_SDA
I2C_SCL
duration less than the deglitch time will be ignored. If the
pulse on the VDDIO lasts longer than the deglitch time, a
reset from the VDDIO is detected to generate a reset signal.
To effectively reset the 34825, the reset pulse from the
VDDIO needs be longer than the 150 s minimum reset
pulse width given in the Dynamic Electrical Characteristics
table.
SOFTWARE RESET
In addition to the two hardware reset types, the system
reset has another reset source, the software reset by writing
‘1’ to the RESET bit in the Control register. The Reset bit will
be cleared to ‘0’ at once since it is of W/C type. The
consequence of the software reset is the same as the
hardware reset. All registers will be reset.
I2C-Bus
Reset
Detection
VDD
+
Delay
Time
-
reset
VVDDPOR
VDDIO
VDDIO
Reset
Detection
Figure 19. Sources of Reset in 34825
8.8~13.5ms
Reset
I2C_SDA
I2C_SCL
Reset
Condition
Start
Condition
Stop
Condition
Figure 20. Hardware Reset Using the I2C Bus
34825
26
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DEVICE OPERATION
I2C SERIAL BUS INTERFACE
tVDDIODGT_F
Reset
VDDIO
Figure 21. Hardware Reset Using the VDDIO Input
INTERRUPT
There are eight interrupt sources in the 34825 causing an
interrupt at the INT pin to the host IC. They are accessory
attachment, accessory detachment, short-key press, long
key press, long-pressed key release, VBUS voltage OVP, the
IC temperature OTP, and either the OVP or the OTP
condition is removed. The 34825 detects each event and sets
the corresponding bit in the Interrupt register. As long as the
Interrupt register is set, the INT pin outputs low voltage. The
Interrupt register is not writable. When the Interrupt register is
read, the Interrupt register is cleared automatically. Once the
Interrupt register is cleared, the INT pin returns to high
voltage.
An interrupt mask register is provided to mask unwanted
interrupt source. When the bit of the Interrupt Mask register
is set to 1, the corresponding interrupt source is blocked. The
INT does not output low voltage even though this interrupt bit
is set in the Interrupt register.
LOGIC OUTPUT
There are two open-drain logic output pins, INT and ISET.
The INT pin is related to the interrupt sources as described in
the Interrupt section. The ISET pin is controlled by the
register bit with the same name in the Control register.
The ISET generally is used to control the charge current
level. A typical charger IC uses one external resistor to set
the charge current. By using ISET output, the charger IC can
use two external resistors in parallel to set two charge current
levels, as shown in Figure 27.
I2C SERIAL BUS INTERFACE
The I2C bus is enabled in the Standby, the Power Save,
and the Active modes. The serial clock (SCL) and the serial
data (SDA) lines must be connected to a positive supply
using pull-up resistors. Internally the I2C bus voltage is
referenced to the VDDIO input. The 34825 is a slave device.
Maximum data rate is 400 kbps.
ADDRESSING AND PROTOCOL
0
1
0
0
1
0
1
R/W
Figure 22. I2C Slave Address
The following three figures show three I2C-bus transaction
protocols. The Word Address is an 8-bit register address in
the 34825.
The 7-bit address for the 34825 is 0100101, as shown in
Figure 22.
Figure 23. Master Transmits to Slave (Write Mode)
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
27
FUNCTIONAL DEVICE OPERATION
REGISTER MAP
Figure 24. Master Reads After Setting Word Address (Write Word Address and then Read Data)
Figure 25. Master Reads Slave Immediately after First Byte (Read Mode)
REGISTER MAP
Table 10. Register Map
Addr
Register
Type
Reset
Value
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
83H
Interrupt
R/C
00000000
OVP_OTP_DIS
OTP_EN
OVP_EN
LKR
LKP
KP
DETACH
ATTACH
85H
Interrupt Mask
R/W
00000000 OVP_OTP_DIS_m
OTP_EN_m
OVP_EN_m
LKR_m
LKP_m
KP_m
DETACH_m
ATTACH_m
87H
ADC Result
R
00011111
Reserved
Reserved
88H
Timing Set
R/W
00000000
93H
S/W Control 1
R/W
00000001
94H
S/W Control 2
R/W
00000100
Reserved
Reserved
Reserved
ISETB
Reserved
Reserved
A0H
Status
R
0x000xxx
Reserved
FET_STATUS
USB_CHG
DP/DM_SHORT
ID_GND
ID_FLOAT
VBUS_DET
ADC_STATUS
A1H
Control
R/W
011000x0
Reserved
Reserved
AutoPSAVE
Reserved
Reserved
RESET
Reserved
Reserved
A2H
Time Delay
R/W
10010100
Reserved
Reserved
Reserved
Reserved
A3H
Device Mode
R/W
00000001
Reserved
Reserved
Reserved
Reserved
ACTIVE
RST
Reserved
ADC Value
Key Press
Long Key Press
Reserved
DP/DM Switching
VBUS Switching
Reserved
TD
Reserved
PSAVE
34825
28
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DEVICE OPERATION
REGISTER MAP
Table 11. Interrupt Register
Bit
Mode
Symbol
Reset
Description
0
R/C
ATTACH
0
1: accessory attached
1
R/C
DETACH
0
1: accessory detached
2
R/C
KP
0
1: remote controller short key is pressed
3
R/C
LKP
0
1: remote controller long key is pressed
4
R/C
LKR
0
1: remote controller long key is released
5
R/C
OVP_EN
0
1: VBUS voltage higher than the OVP threshold
6
R/C
OTP_EN
0
1: The temperature of 34825 is above the OTP threshold
7
R/C
OVP_OTP_DIS
0
1: OVP or OTP event is removed
Notes
Table 12. Interrupt Mask Register
Bit
Mode
Symbol
Reset
0
R/W
ATTACH_m
0
1: interrupt disabled
1
R/W
DETACH_m
0
1: interrupt disabled
2
R/W
KP_m
0
1: interrupt disabled
3
R/W
LKP_m
0
1: interrupt disabled
4
R/W
LKR_m
0
1: interrupt disabled
5
R/W
OVP_EN_m
0
1: interrupt disabled
6
R/W
OTP_EN_m
0
1: interrupt disabled
7
R/W
OVP_OTP_DIS_m
0
1: interrupt disabled
Description
Notes
Description
Notes
Description
Notes
Table 13. ADC Result Register
Bit
Mode
Symbol
Reset
4-0
R
ADC Result
11111
7-5
R
Reserved
000
ADC Result of the ID resistor
Table 14. Timing Set Register
Bit
Mode
Symbol
Reset
3-0
R/W
Long Key Press
0000
Long key press duration
0000: 300 ms
0001: 400 ms
0010: 500 ms
......
7-4
R/W
Key Press
0000
Normal key press duration
0000: 100 ms
0001: 200 ms
0010: 300 ms
......
Table 15. Timing Table
Setting Value
Key Press
Long Key Press
0000
100 ms
300 ms
0001
200 ms
400 ms
0010
300 ms
500 ms
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
29
FUNCTIONAL DEVICE OPERATION
REGISTER MAP
Table 15. Timing Table (continued)
Setting Value
Key Press
Long Key Press
0011
400 ms
600 ms
0100
500 ms
700 ms
0101
600 ms
800 ms
0110
700 ms
900 ms
0111
800 ms
1000 ms
1000
900 ms
1100 ms
1001
1000 ms
1200 ms
1010
-
1300 ms
1011
-
1400 ms
1100
-
1500 ms
1101
-
-
1110
-
-
1111
-
-
Table 16. S/W Control Register 1
Bit
Mode
Symbol
Reset
Description
1-0
R/W
VBUS Switching
01
VBUS line switching configuration
00: open all switches connected to the VBUS line.
01: internal power MOSFET on
10: VBUS connected to MIC
11: open all switches connected to the VBUS line.
4-2
R/W
DP/DM Switching
000
DP/DM line switching configuration
000: open all switches
001: DP connected to D+, DM connected to D010: DP connected to SPK_R, DM connected to SPK_L
011: DP connected to RxD, DM connected to TXD
Others: open all switches connected to the DP pin and DM pin
7-5
R
Reserved
000
Notes
Table 17. S/W Control Register 2
Bit
Mode
Symbol
Reset
3-0
R/W
Reserved
0100
4
R/W
ISETB
0
7-5
R/W
Reserved
000
Description
Notes
ISET output
0: high-impedance
1: low-impedance
34825
30
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DEVICE OPERATION
REGISTER MAP
Table 18. Status Register
Bit
Mode
Symbol
Reset
Description
0
R
ADC_Status
x
ADC conversion status
1: ADC conversion completed
0: ADC in progress
1
R
VBUS_DET
x
VBUS voltage is higher than the POR
0: no
1: yes
2
R
ID_FLOAT
x
ID line is floating
0: no
1: yes
3
R
ID_GND
0
ID pin is shorted to ground
0: no
1: yes
4
R
DP/DM_SHORT
0
DP/DM shorted
0: no
1: yes
5
R
USB_CHG
0
A USB charger is connected
0: no
1: yes
6
R
FET_STATUS
x
The on/off status of the power MOSFET
0: off
1: on
7
R
Reserved
0
Notes
Table 19. Control Register
Bit
Mode
Symbol
Reset
1-0
R/W
Reserved
x0
2
W/C
RESET
0
4-3
R/W
Reserved
00
5
R/W
AutoPSAVE
1
7-6
R/W
Reserved
01
Description
Notes
Soft reset. When written to 1, the IC is reset. Once the reset is complete,
the RST bit is set and the RESET bit is cleared automatically.
1: to soft reset the IC
Automatic Power Save mode detection control
0: disable automatic Power Save mode detection. Device can enter Power
Save mode via the I2C
1: enable automatic Power Save mode detection.
Table 20. Time Delay Register
Bit
Mode
Symbol
Reset
3-0
R/W
TD
0100
7-4
R/W
Reserved
1001
Description
Notes
Time delay to start the powered accessory identification flow after
detecting the VBUS voltage
0000: 100 ms
0001: 200 ms
0010: 300 ms
0011: 400 ms
0100: 500 ms
......
1111:1600 ms
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
31
FUNCTIONAL DEVICE OPERATION
REGISTER MAP
Table 21. Device Mode Register
Bit
Mode
Symbol
Reset
Description
0
R/C
RST
1
This bit indicates if a chip reset has occurred. This bit will be cleared once
being read.
0: no.
1: Yes.
1
R/W
ACTIVE
0
Indicate either the device is in Active mode
0: Standby
1: Active
2
R/W
PSAVE
0
To indicate either the device is in Power Save mode
0: no
1: yes
Reserved
00000
7-3
Notes
34825
32
Analog Integrated Circuit Device Data
Freescale Semiconductor
TYPICAL APPLICATIONS
APPLICATION INFORMATION
TYPICAL APPLICATIONS
APPLICATION INFORMATION
ID RESISTANCE VALUE ASSIGNMENT
Table 22. ID Resistance Assignment: (Unit: k)
The ID resistors used with the 34825 are standard 1%
resistors. Table 22 lists the complete 32 ID resistor
assignment. The ones with the assigned functions filled are
the ones that are already used with special functions. The
ones reserved can be assigned to other functions.
Table 22. ID Resistance Assignment: (Unit: k)
Item#
0
1
ADC Result
00000
ID Resistance
<1.9
Assignment
Reserved
Item#
ADC Result
ID Resistance
Assignment
26
11010
365
Reserved
27
11011
442
Carkit Charger
Type 2
28
11100
523
Reserved
29
11101
619
R/C Accessory 1
30
11110
1000
R/C Accessory 2
31
11111
-
ID float
00001
2.0
S0
2
00010
2.604
S1
3
00011
3.208
S2
The remote control architecture is illustrated in Figure 26.
The recommended resistors for the remote control resistor
network are given in Table 23.
4
00100
4.014
S3
Table 23. Remote Control Resistor Values (Unit: k)
5
00101
4.820
S4
6
00110
6.03
S5
7
00111
8.03
S6
8
01000
10.03
S7
9
01001
12.03
S8
10
01010
14.46
S9
11
01011
17.26
S10
12
01100
20.5
S11
13
01101
24.07
S12
14
01110
28.7
UART Test Cable 1
15
01111
34.0
UART Test Cable 2
16
10000
40.2
USB Test Cable 1
17
10001
49.9
USB Test Cable 2
18
10010
64.9
Reserved
19
10011
80.6
Reserved
20
10100
102
Reserved
21
10101
121
Reserved
22
10110
150
Reserved
23
10111
200
Carkit Charger
Type 1
24
11000
255
Reserved
25
11001
301
Reserved
Resistor
Standard Value
ID Resistance
R1
2.0
2.0
R2
0.604
2.604
R3
0.604
3.208
R4
0.806
4.014
R5
0.806
4.82
R6
1.21
6.03
R7
2.0
8.03
R8
2.0
10.03
R9
2.0
12.03
R10
2.43
14.46
R11
2.8
17.26
R12
3.24
20.5
R13
3.57
24.07
R14
590/976
614/1000
ID
R1
R2
R13
R3
…...
S0
GND
S1
S2
S12
R14
HOLD
Figure 26. Remote Control Architecture
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
33
TYPICAL APPLICATIONS
TYPICAL APPLICATIONS
DECOUPLING CAPACITOR
Decoupling capacitors are required at all power supply
input and output pins. For the VDD pin, a X5R capacitor of
1.0 F is recommended. For VBUS pin, because it also acts
as the microphone input, the decoupling capacitance at
VBUS pin must be carefully considered. Assuming the voice
band is 3.4 kHz and the pull-up resistance for the microphone
is 2.0 k, the decoupling capacitance at the VBUS pin should
be less than 22 nF. A 4.7 nF X5R capacitor is recommended
for the typical application. The OUT pin requires a 1.0 F
decoupling capacitor; a 0.01 F capacitance is enough for
the VDDIO pin.
TYPICAL APPLICATIONS
INTERFACE CIRCUIT IN A CELL PHONE
When the 34825 is used in a cell phone. The typical circuit
is shown in the Figure 27. The I2C bus need two pull-up
resistors. Typically they are 4.7 kWhen the audio outputs
of the cell phone baseband or application processor are
direct drive signals, the audio signals can be connected to the
corresponding pins of 34825 directly. Otherwise these
signals need DC-blocking capacitors to remove the DC level.
VDDIO
2x4.7 k
Baseband
VDD
2
I C_SDA
I2C_SCL
INT
VDDIO
I2C
GPIO
RxD
TxD
UART
D+
D-
USB Xcvr
1.0 µF
12 k
MC34673
1.0 µF
9.1 k
ISET
OUT
VBUS
VBUS
4.7 nF
VAIO
2k
0.1 µF
Audio
Li+
MIC
*
*
SPK_L
SPK_R
ID
DP
DM
GND
ID
D+
DGND
SHLD
* : For direct-drive audio output, these DC
blocking capacitors are not needed
Figure 27. Interface Circuit in a Cell Phone System
34825
34
Analog Integrated Circuit Device Data
Freescale Semiconductor
TYPICAL APPLICATIONS
PACKAGE DIMENSIONS
PACKAGE DIMENSIONS
For the most current package revision, visit www.freescale.com and perform a keyword search using the “98A” listed below.
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
35
TYPICAL APPLICATIONS
PACKAGE DIMENSIONS
34825
36
Analog Integrated Circuit Device Data
Freescale Semiconductor
TYPICAL APPLICATIONS
PACKAGE DIMENSIONS
34825
Analog Integrated Circuit Device Data
Freescale Semiconductor
37
REVISION HISTORY
REVISION HISTORY
Revision
Date
2.0
3/2010
3.0
6/2014
4.0
9/2014
Description of Changes
•
Initial Release
•
No technical changes. Revised back page. Updated document properties. Added SMARTMOS
sentence to last paragraph.
•
Updated 98A to 98ASA00716D
34825
38
Analog Integrated Circuit Device Data
Freescale Semiconductor
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© 2014 Freescale Semiconductor, Inc.
Document Number: MC34825
Rev 4.0
9/2014
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