2
Extremely Accurate I C-Integrated
RTC/TCXO/Crystal
DS231
Revision History
REVISION REVISION
PAGES
DESCRIPTION
CHANGED
NUMBER
DATE
0
1/05
Initial release.
—
1, 3
1
Changed Digital Temp Sensor Output from ±2°C to ±3°C.
Updated Typical Operating Circuit.
1
2/05
Changed T = -40°C to +85°C to T = T
to T .
MAX
2, 3, 4
8
A
A
MIN
Updated Block Diagram.
Added “UL Recognized” to Features; added lead-free packages and removed S
from top mark info in Ordering Information table; added ground connections to the
N.C. pin in the Typical Operating Circuit.
1
Added “noncondensing” to operating temperature range; changed V MIN from
PF
2.35V to 2.45V.
2
Added aging offset specification.
Relabeled TOC4.
3
7
Added arrow showing input on X1 in the Block Diagram.
8
Updated pin descriptions for V and V
CC
.
9
BAT
2
6/05
2
Added the I C Interface section.
10
11
13
Figure 1: Added sign bit to aging and temperature registers; added MSB and LSB.
Corrected title for rate select bits frequency table.
Added note that frequency stability over temperature spec is with aging offset
register = 00h; changed bit 7 from Data to Sign (Crystal Aging Offset Register).
14
15
17
Changed bit 7 from Data to Sign (Temperature Register); correct pin definitions in
2
I C Serial Data Bus section.
Modified the Handing, PC Board Layout, and Assembly section to refer to
J-STD-020 for reflow profiles for lead-free and leaded packages.
3
4
11/05
10/06
Changed lead-free packages to RoHS-compliant packages.
1
1
Changed RST and UL bullets in Features.
Changed EC condition “V > V
” to “V = Active Supply (see Table 1).”
2, 3
6
CC
BAT
CC
Modified Note 12 to correct t
operation.
REC
Added various conditions text to TOCs 1, 2, and 3.
7
Added text to pin descriptions for 32kHz, V , and RST.
CC
9
Table 1: Changed column heading “Powered By” to “Active Supply”; changed
10
13
14
“applied” to “exceeds V ” in the Power Control section.
PF
Indicated BBSQW applies to both SQW and interrupts; simplified temp convert
description (bit 5); added “output” to INT\SQW (bit 2).
Changed the Crystal Aging section to the Aging Offset section; changed “this bit
indicates” to “this bit controls” for the enable 32kHz output bit.
Added Warning note to EC table notes; updated Note 12.
6
7
Updated the Typical Operating Characteristics graphs.
In the Power Control section, added information about the POR state of the time and
date registers; in the Real-Time Clock section, added to the description of the RST
function.
5
4/08
10
11
In Figure 1, corrected the months date range for 04h from 00–31 to 01–31.
____________________________________________________________________ 19
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
