Power management, Sleep mode (<10 µa), Acquisition mode current consumption – Rainbow Electronics AT77C105A User Manual
Page 32: Static current consumption, Dynamic current consumption, Reset high, Pins
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AT77C105A [Preliminary]
5419A–BIOM–01/05
The dissipated die power is quasi constant over a significant supply voltage range as
shown below (mode 50 mW selected):
Figure 18.
Note:
This function is useless for navigation and click modes.
Power Management
Sleep Mode (<10 µA)
Reset high
Standby Mode
(<10 µA Providing SPI
Bus not Accessed)
Power consumption can be reduced in several ways:
•
By switching off the FingerChip sensor.
•
By programming a standby mode by writing 00001xx in the MODCTRL register
(STANDBY mode set and oscillator stopped.) Bit b6 (HEAT) of the HEATCTRL
register must be turned to ‘0’ when programming standby mode.
Acquisition Mode
Current Consumption
Static Current Consumption
When the SPI bus is not used, only the analog part of the circuit consumes power at
around 4 mA.
Dynamic Current
Consumption
When the clock is running, the digital sections also consume current. With a 30 pF load
at 16 MHz, the power consumption is approximately 4.5 mA on the V
DD
pins.
Power = f ( Vdd )
4,80E-02
4,90E-02
5,00E-02
5,10E-02
5,20E-02
5,30E-02
5,40E-02
2
2,2
2,4
2,6
2,8
3
3,2
3,4
3,6
3,8
VDD
Po
w
e
r (
W
)
Power = f ( Vdd)