AIT1042
PROGRAMMING THE AIT1042
ThisꢀsectionꢀdescribesꢀhowꢀtoꢀprogramꢀtheꢀregistersꢀofꢀtheꢀAIT1042ꢀtoꢀcontrolꢀitsꢀoperation.ꢀꢀTheꢀ24-bitꢀregistersꢀ
thatꢀcontrolꢀtheꢀdividersꢀandꢀotherꢀfunctionsꢀareꢀeachꢀsegmentedꢀintoꢀthreeꢀ8-bitꢀdataꢀwords.ꢀSomeꢀbitsꢀhaveꢀ
requiredꢀfixedꢀvaluesꢀ(reservedꢀbitsꢀandꢀaddressing),ꢀwhileꢀothersꢀareꢀusedꢀforꢀcontrolꢀandꢀsynthesizerꢀoperation.ꢀ
TheꢀgrayedꢀareasꢀofꢀtheꢀaddressesꢀandꢀcontrolꢀregistersꢀareꢀfixedꢀvaluesꢀandꢀmustꢀbeꢀsetꢀasꢀindicatedꢀinꢀTable
8.
Control Register I
Controlꢀregister Iꢀhasꢀtwoꢀuserꢀprogrammableꢀfunctions:
•ꢀ Wake-upꢀ(Bitꢀ19)
•ꢀ Chargeꢀpumpꢀcurrentꢀsettingsꢀ(Bitsꢀ8-10ꢀandꢀbitsꢀ12-14)ꢀinꢀtheꢀsynthesizers
Table 9ꢀshowsꢀhowꢀtheꢀWake-upꢀbitꢀisꢀusedꢀtoꢀcontrolꢀpowerꢀupꢀofꢀtheꢀAIT1042.ꢀWhenꢀtheꢀdeviceꢀisꢀinitiallyꢀ
poweredꢀupꢀtheꢀwakeꢀupꢀbitꢀ(19)ꢀisꢀsetꢀtoꢀ0ꢀandꢀtheꢀdeviceꢀwillꢀdrawꢀminimumꢀcurrent.ꢀSettingꢀbitꢀ19ꢀtoꢀ1ꢀwillꢀ
turnꢀtheꢀdeviceꢀonꢀforꢀnormalꢀoperation.
Theꢀchargeꢀpumpꢀcurrentꢀsettingsꢀforꢀtheꢀupconverterꢀ(CPI1)ꢀandꢀdownconverterꢀ(CPI2)ꢀsynthesizersꢀareꢀ
setꢀbyꢀBitsꢀ8-10ꢀandꢀBitsꢀ12-14,ꢀrespectively.ꢀReferꢀtoꢀTable 10.ꢀ
Table 8: Control Register I
PLL_CtrlI (Control Register I)
LSB
MSB
Firstꢀdataꢀbyte
Secondꢀdataꢀbyte
Thirdꢀdataꢀbyte
23 22 21 20 19 18 17 16 15 14 13 12 11 10
CPI2
9
8
7
1
6
0
5
0
4
0
3
0
2
0
1
0
0
1
0
1
0
0
W
0
0
0
0
0
CPI1
Table 10: Charge Pump Current Bits
Table 9: Wake-up Mode Bit
CPIx Bits
0000
0001
0010
0011
Charge Pump Current
(reserved)
0.7ꢀmA
Bit 19
Wake-up mode
Powerꢀdownꢀ(default)
Normalꢀoperation
0
1
1.3ꢀmA
1.9ꢀmA
0100
0101
0110
2.5ꢀmA
3.1ꢀmA
3.6ꢀmA
0111
4.1ꢀmA
Note: 1000 thru 1111 are Reserved.
PRELIMINARY DATA SHEET - Rev 1.0
12
02/2009
ANADIGICS [ ANADIGICS, INC ]
