90E32A_14 Datasheet, PDF (66/71 Pages) ATMEL Corporation – Poly-Phase High-Performance

90E32A
POLY-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC
7.4 POWER ON RESET TIMING
In most case, the power of 90E32A and MCU are both derived from
220V power lines. To make sure 90E32A is reset and can work properly,
MCU must force 90E32A into idle mode firstly and then into normal
mode. In this operation, RESET is held to high in idle mode and de-
asserted by delay T1 after idle-normal transition. Refer to Figure-18.
DVDD
T0
PM[1:0]
MCU startup
Idle Mode
Normal Mode
T1
RESET
Figure-18 Power On Reset Timing (90E32A and MCU are Powered on Simultaneously)
DVDD
V_H
T1
RESET
Figure-19 Power On Reset Timing in Normal & Partial Measurement Mode
Table-17 Power On Reset Specification
Symbol
Description
Min
Typ
Max
Unit
V_H
Power On Trigger Voltage
2.5
2.7
V
T₀
Duration forced in idle mode after power on
1
ms
T₁
Delay time after power on or exit idle mode
5
16
40
ms
Electrical Specification
66
April 2, 2013