AT73C237 Atmel, AT73C237 Datasheet - Page 7

• Manufacturer Part Number: AT73C237
• Description: IC POWER MANAGEMENT UNIT 16QFN
• Manufacturer: Atmel

Specifications of AT73C237

• Applications: Wireless
• Current - Supply: 250µA
• Voltage - Supply: 2.8 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

6. Startup Procedure
6.1
6.2
6362A–PMAAC–01-Jul-08
At VDD4 Rising
At VDD3 Falling
Both XRESIN and the Supply Monitor on VDD3 are debounced at rising and falling edges for
two 10 kHz clock cycles. The debounce time is typically between 100 µs and 200 µs. Timings
are defined ± 40%.
• LPBG, LDO4, RCOSC start up
• POR connected to LDO4 output VO4 resets the state machine and enables:
• The Supply monitor generates a shut down control signal when VDD3 reaches 2.6V
• The State machine sets XRESO to logic “0”.
• The State machine switches off LDO1, LDO2, LDO3. HPBG is kept enabled in order to
assure a fast new startup of the LDOs.
– The reading of the internal fuses (TRIM cell in the application diagram) in order to
– The Two Wire Interface
– Then under control of the state machine:
a. HPBG is turned on
b. After 4 ms, the Supply Monitor on VDD3 is turned on.
c. If VDD3 is present and greater than 2.7V, LDO1, 2, 3 are turned on. During LDO
d. Then XRESO is kept grounded for 180 ms, and set to “1” for 1ms before following
set up the programmed output voltage of LDO1, LDO2, LDO3, and the correct
reference voltage and oscillation frequency
regulator startup VDD3 voltage is checked.
XRESIN. During that state VDD3 voltage is monitored and if lower than 2.6V, LDO
regulators 1, 2 and 3 are stopped and XRESO grounded.
AT73C237
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