FT221XQ-R International Semiconductor Technologies, FT221XQ-R Datasheet - Page 29

• Manufacturer Part Number: FT221XQ-R
• Description: Specifications: Applications: * ; Interface: * ; Voltage - Supply: 3.3 V ~ 5 V ; Package / Case: 20-VFQFN Exposed Pad ; Packaging: Digi-Reel
• Manufacturer: International Semiconductor Technologies

7.4 USB Battery Charging Detection
A recent addition to the USB specification (
is to allow for additional charging profiles to be used for charging batteries in portable devices. These
charging profiles do not enumerate the USB port of the peripheral. The FT221X device will detect that a
USB compliant dedicated charging port (DCP) is connected. Once detected while in suspend mode a
battery charge detection signal is provided to allow external logic to switch to charging mode as opposed
to operation mode.
Figure 7.4 USB Battery Charging Detection
To use the FT221X with battery charging detection the CBUS pin must be reprogrammed to allow for the
BCD Charger output to switch the external charger circuitry on. The CBUS pins are configured in the
internal MTP memory with the free utility FTPROG. If the charging circuitry requires an active low signal
to enable it, the CBUS pin can be programmed to BCD Charger# as an alternative.
When connected to a USB compliant dedicated charging port (DCP, as opposed to a standard USB host)
the device USB signals will be shorted together and the device suspended. The BCD charger signal will
bring the LTC4053 out of suspend and allow battery charging to start. The charge current in the example
above is 1A as defined by the resistance on the PROG pin.
To calculate the equivalent resistance on the LTC4053 PROG pin select a charge current, then Res =
1500V/I
For more configuration options of the LTC4053 refer to: AN_175_Battery Charging Over USB
0.1uF
VBUS
GND
EEPROM Setting
X-Chip Pin
CBUS3
VBUS
CN USB
GND
SLD
chg
4.7uF
VBUS
GND
D+
GND
D-
ID
0R
N.F.
1
2
3
4
5
Function
0.1uF
VBUS
GND
GND
BCD
Copyright © 2013 Future Technology Devices International Limited
10nF
600R/2A
VBUS
GND
27R
27R
0.1uF
Battery Charger Enable
3V3OUT
1
2
3
4
5
De-acticate Sleep
GND
Battery Options
Force Power Enable
CHRG
VCC
GND
FAULT
TIMER
DM
DP
3V3OUT
RESET#
GND
VBUS
LTC4053EDD
ACPR
SHDN
PROG
BAT
NTC
GND
X
3V3OUT
http://www.usb.org/developers/devclass_docs/BCv1.2_011912.zip
10
9
8
7
6
JUMPER-2mm
CBUS3
GND
2K2
FT221X
VBUS
4K32 1%
GND
1K5
BCD
NTC
JP1
SIP-3
BCD
NTC
0A when in sleep
0A when enumerated
0.1uF
Document No.: FT_000630 Clearance No.: FTDI# 263
0A when not enumerated and not in sleep
1A when connected to a dedicated charger port
VBUS
GND
VBATT
GND
GND
1R
1uF
3V3OUT
GND
GND
JP1
1-2
2-3
NCT Available
0.1uF
NCT Enabled
NCT Disabled (Default)
TB3.5mm
1
-
+
NCT
Version 1.2
)
29