Rainbow Electronics AT83C26 - Manual (Page 23)

23
7511B–SCR–10/05
AT83C26
LDO initialization
Procedure
When the DC/DC B voltage rises the selected voltage (VDCB_OK=1), the card voltage selection
on CVCC2, CVCC3, CVCC4 or CVCC5 starts the corresponding LDO.
The CVCC2 card voltage must be started in first (if needed). When the VCARD_OK2 is set, the
CVCC3,CVCC4, CVCC5 card voltage are started one after each other (if needed) with the same
procedure.
The SC2_FULL bit must be set to use SC2 full interface:
CIO3/CC42 is CC42 and CRST3/CC82 is CC82.
As the power supply of CIO3/CC42 and of CRST3/CC82 is CVCC3, when SC2_FULL=1,
CVCC3 = CVCC2. The SC3 interface is disable and LDO3 receives LDO2 command
(VCARD3[1:0] = VCARD2[1:0]).
Figure 11. LDOn Initialization Procedure (n = 2, 3, 4, 5)
The LDOn output voltage must be at 0V before to program 1.8V/3V/5V.
Init condition:
DCDCB started
(VDCB_OK = 1)
Start LDOn,
write VCARDn[1:0]
VCARD_OKn = 1
Time-out Expired
and IPLUSn=1
?
LDOn initialization
failure
IPLUSn = 1
Set Timer 2ms
LDOn started