ISL12022MR5421 Datasheet, PDF (18/29 Pages) Intersil Corporation – Low Power RTC with Battery Backed SRAM, Integrated 5ppm

ISL12022MR5421
user. If an application requires adjustment of the
IATR bits outside the preset values, the user
should contact Intersil.
AGING AND INITIAL TRIM DIGITAL TRIMMING
BITS (IDTR0<1:0>)
These bits allow ±30.5ppm initial trimming range for the
crystal frequency. This is meant to be a coarse
adjustment if the range needed is outside that of the
IATR control. See Table 10. The IDTR0 register should
only be changed while the TSE (Temp Sense Enable) bit
is “0”.
The ISL12022MR5421 has a preset Initial Digital
Trimming value corresponding to the crystal in the
module. This value is recalled on initial power-up
and is READ-ONLY. It cannot be overwritten by the
user.
TABLE 10. IDTR0 TRIMMING RANGE
IDTR01
IDTR00
TRIMMING RANGE
0
0
Default/Disabled
0
1
+30.5ppm
1
0
0ppm
1
1
-30.5ppm
AGING AND INITIAL ANALOG TRIMMING BITS
(IATR0<5:0>)
The Initial Analog Trimming Register allows +32ppm to
-31ppm adjustment in 1ppm/bit increments. This
enables fine frequency adjustment for trimming initial
crystal accuracy error or to correct for aging drift.
The ISL12022MR5421 has a preset Initial Analog
Trimming value corresponding to the crystal in the
module. This value is recalled on initial power-up, is
preset in device production and is READ-ONLY. It
cannot be overwritten by the user.
TABLE 11. INITIAL AT AND DT SETTING REGISTER
ADDR 7
6
5
4
3
2
1
0
0Bh IDTR01 IDTR00 IATR05 IATR04 IATR03 IATR02 IATR01 IATR00
TABLE 12. IATRO TRIMMING RANGE
TRIMMING
IATR05 IATR04 IATR03 IATR02 IATR01 IATR00 RANGE
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
1
0
0
0
0
0
1
1
0
0
0
1
0
0
0
0
0
1
0
1
0
0
0
1
1
0
0
0
0
1
1
1
0
0
1
0
0
0
0
0
1
0
0
1
0
0
1
0
1
0
0
0
1
0
1
1
+32
+31
+30
+29
+28
+27
+26
+25
+24
+23
+22
+21
TABLE 12. IATRO TRIMMING RANGE (Continued)
TRIMMING
IATR05 IATR04 IATR03 IATR02 IATR01 IATR00 RANGE
0
0
1
1
0
0
0
0
1
1
0
1
0
0
1
1
1
0
0
0
1
1
1
1
0
1
0
0
0
0
0
1
0
0
0
1
0
1
0
0
1
0
0
1
0
0
1
1
0
1
0
1
0
0
0
1
0
1
0
1
0
1
0
1
1
0
0
1
0
1
1
1
0
1
1
0
0
0
0
1
1
0
0
1
0
1
1
0
1
0
0
1
1
0
1
1
0
1
1
1
0
0
0
1
1
1
0
1
0
1
1
1
1
0
0
1
1
1
1
1
1
0
0
0
0
0
1
0
0
0
0
1
1
0
0
0
1
0
1
0
0
0
1
1
1
0
0
1
0
0
1
0
0
1
0
1
1
0
0
1
1
0
1
0
0
1
1
1
1
0
1
0
0
0
1
0
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
1
1
0
1
1
0
0
1
0
1
1
0
1
1
0
1
1
1
0
1
0
1
1
1
1
1
1
0
0
0
0
1
1
0
0
0
1
1
1
0
0
1
0
1
1
0
0
1
1
1
1
0
1
0
0
1
1
0
1
0
1
1
1
0
1
1
0
1
1
0
1
1
1
1
1
1
0
0
0
1
1
1
0
0
1
1
1
1
0
1
0
1
1
1
0
1
1
1
1
1
1
0
0
1
1
1
1
0
1
1
1
1
1
1
0
1
1
1
1
1
1
+20
+19
+18
+17
+16
+15
+14
+13
+12
+11
+10
+9
+8
+7
+6
+5
+4
+3
+2
+1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
-14
-15
-16
-17
-18
-19
-20
-21
-22
-23
-24
-25
-26
-27
-28
-29
-30
-31
18
FN7576.1
June 4, 2010