Freescale Semiconductor
Technical Data
Document Number: MC34825
Rev 3.0, 6/2014
Micro-USB Interface IC
Supporting Universal Charging
Solution and Wired Accessories
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, such as a dedicated ac/dc adapter or a USB port, to charge
the battery. 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 over-voltage protection (OVP) to the cell
phone against failed power supplies. The 34825 also contains analog
switches to multiplex the 5 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 research-
and-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 I
2
C 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 battery-
charging-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
• I
2
C interface
• 10
μA
quiescent current in Standby mode
Baseband
GPIO
I2C
UART
USB XCVR
AUDIO
34825
INTERFACE IC
(PB-FREE)
98ASA00037D
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
D-
SPK_L
ID
SPK_R
DP
MIC
DM
GND
LI+
Charger
V
BUS
ID
D+
D-
GND
USB Connector
Figure 1. 34825 Simplified Application Diagram
© Freescale Semiconductor, Inc., 2010 - 2014. All rights reserved.
PIN CONNECTIONS
PIN CONNECTIONS
VBUS
17
20
19
18
16
15
14
13
12
11
TRANSPARENT
TOP VIEW
SPK_R
SPK_L
MIC
D+
D-
ISET
DM
DP
ID
1
2
3
4
5
6
7
8
9
10
OUT
I
2
C_SCL
I
2
C_SDA
INT
VDD
21
GND
VDDIO
RXD
TXD
NC
Figure 3. 34825 Pin Connections
Table 2. 34825 Pin Definitions
A functional description of each pin can be found in the Functional Pin Description section on
page 14.
Pin Number
1
2
3
4
5
6
7
8
9
Pin Name
SPK_R
SPK_L
MIC
D+
D-
RXD
TXD
NC
VDDIO
Pin Function
Input
Input
Output
IO
IO
Output
Input
No Connection
Input
Formal Name
Definition
Speaker right channel Right channel input for speaker signals
Speaker left channel
Microphone output
D+ of the USB
transceiver
D- of the USB
transceiver
UART receiver
UART transmitter
No Connection
IO power supply
Left channel input for speaker signals
Microphone output to the baseband of the cell phone system
D+ line of the USB transceiver
D- line of the USB transceiver
Receive line of the UART
Transmit line of the UART
No Connection
IO supply voltage. The VDDIO voltage is used as the reference voltage
for the I
2
C bus signals. This pin also functions as a hardware reset to
the IC.
No Connection
IC power supply input
Open-drain interrupt output
Data line of the I
2
C interface
Clock line of the I
2
C interface
The output of the power MOSFET pass switch
10
11
12
13
14
15
16
17
18
NC
VDD
INT
I
2
C_SDA
I
2
C_SCL
OUT
ISET
VBUS
DM
No Connection
Input
Output
IO
Input
Output
Output
Input
IO
No Connection
Power supply
Interrupt output
I
2
C data
I
2
C clock
Power output
Charge current setting Open-drain output to set the charger current
VBUS power supply
D- of the USB
connector
VBUS line of the Mini or micro-USB connector
D- line of the mini or micro-USB connector
34825
NC
4
Analog Integrated Circuit Device Data
Freescale Semiconductor
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