Power
Rev 6 Mar.13
Proprietary and Confidential - Contents subject to change
53
Figure 6-1: Voltage / temperature monitoring state machines
Power interface
Power ramp-up
On inital power up, inrush current depends on the power supply rise time — turn
on time >100 µs is required for < 3A inrush current.
The supply voltage must remain within specified tolerances while this is occurring.
Power-up timing
The unit is ready to enumerate with a USB host within a maximum of 3–5
seconds after power-up.
illustrates the power-up timing
sequence.
Figure 6-2: Power-up timing diagram
1. Module-reported temperatures at the printed circuit board.
2. Supply voltage — 3.3V
Off mode
Handled by Power
State state machine.
Normal mode
Low power mode
Handled by Power
State state machine.
current_vcc > VOLT_LO_NORM
current_temp <= TEMP_HI_NORM
current_vcc < VOLT_LO_CRIT
current_temp > TEMP_HI_CRIT
current_vcc > VOLT_LO_NORM
current_temp < TEMP_HI_NORM
current_vcc < VOLT_LO_WARN
current_temp > TEMP_HI_WARN
current_vcc < VOLT_HI_NORM
current_temp > TEMP_NORM_LO
current_vcc > VOLT_HI_CRIT
current_temp < TEMP_LO_CRIT
(Manual transition)
Host asserts
W_Disable#
Normal mode
Low supply voltage warning
or
High temperature warning
Enumeration
3.3V
W_Disable#
USB D+
Startup time
