PixArt Imaging Inc.
ADBS-A350 Optical Finger Navigation
DC Electrical Specifications
Electrical Characteristics over recommended operating conditions. Typical values at 25° C, VDD=VDDIO=1.8V at default
LED setting 13 mA.
Parameter
Symbol
I VDDIO
IPEAK VDD
IPEAK LED+
VIL
Minimum Typical
Maximum Units
Notes
VDDIO DC Supply Current
Digital peak supply current
LED+ peak supply current
Input Low Voltage
20
A
mA
mA
V
10
35
At LED register setting of 27 mA
-0.05
0
VDDIO*0.35
IO_MOSI_A0, IO_CLK, IO_MISO_SDA,
IO_NCS_A1, NRST, SHTDWN,
IO_SELECT
Input High Voltage
VIH
VDDIO * 0.7 VDDIO
VDDIO+0.05 V
IO_MOSI_A0, IO_CLK, IO_MISO_SDA,
IO_NCS_A1, NRST, SHTDWN,
IO_SELECT
Input hysteresis
VHYS
Ileak
100
mV
Input leakage current
1
10
A
IO_MOSI_A0, IO_CLK, IO_MISO_SDA,
IO_NCS_A1, NRST, SHTDWN,
IO_SELECT
Output Low Voltage
Output High Voltage
Input Capacitance
VOL
VOH
Cin
0.2
V
Iout = 1.2 mA
VDDIO-0.2 VDDIO-0.1
V
Iout = 600 A
10
pF
MOSI, NCS, SCLK, SHTDWN
Notes on Power-up Sequence
Below is the power up sequence for ADBS-A350:
1. Apply power.
Shorter pulse widths may cause the chip to enter an
undefined state. In addition, the SPI or TWI port of the
sensor should not be accessed when SHTDWN is asserted.
Other devices on the same SPI bus can be accessed, as
long as the sensor’s NCS pin is not asserted. The table
below shows the state of various pins during shutdown.
2. Set NCS pin high, Shutdown pin low. Set IO_Select pin
to low (for TWI) or high (for SPI).
3. If in TWI mode, set A0 and A1 according to the Table
TWI slave address in datasheet. This step is skipped if
SPI mode is used.
After deasserting SHTDWN, wait t
before accessing
WAKEUP
the SPI port. Reinitializing the sensor from shutdown state
will retain all register data that were written to the sensor
prior to shutdown.
4. Read Product ID to ensure sensor is powered up and
communicating properly with host.
The reset of the sensor via SOFT_RESET register or through
the NRST pin would reset all registers to the default value.
Any register settings must then be reloaded.
5. Write 0xC9 to address 0x61.
Note on register settings
Pin
SHTDWN active
Functional
Undefined
Undefined
Undefined
Low current
Undefined
High
Please refer to the OFN A350 firmware design guide for
tuning of Speed Switching, Assert/De-assert, Finger
Presence Detect and XY Quantization register settings.
IO_NCS_A1
IO_MISO_SDA
IO_CLK
Notes on Shutdown and Reset
IO_MOSI_A0
XY_LED
The ADBS-A350 can be set in Shutdown mode by asserting
or setting SHTDWN pin high. During the shutdown state,
supply voltages VDD must be maintained above the
minimum level. If these conditions are not met, then
the sensor must be restarted by powering down then
powering up again for proper operation. Any register
settings must then be reloaded.
EVENT_INT
NRST
IO_Select
GPIO
SPI: High, TWI: Low
Undefined
Note: There are long wakeup times from shutdown. These features
should not be used for power management during normal sensor
motion.
During the shutdown state, supply voltage VDD must
be maintained above the minimum level. For proper
operation,SHTDWNpulsewidthmustbeatleastt
.
P-SHTDWN
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PixArt Imaging Inc.
10
E-mail: fae_service@pixart.com.tw
PIXART [ PIXART IMAGING INC. ]
