ds2437 Maxim Integrated Products, Inc., ds2437 Datasheet - Page 25

• Manufacturer Part Number: ds2437
• Description: Smart Battery Monitor
• Manufacturer: Maxim Integrated Products, Inc.

DS2437
Read Time Slots
The host generates read time slots when data is to be read from the DS2437. A read time slot is initiated
when the host pulls the data line from a logic high level to logic low level. The data line must remain at a
low logic level for a minimum of 1 s; output data from the DS2437 is then valid within the next 14 s
maximum.
The host therefore must stop driving the I/O pin low in order to read its state 15 s from the start of the
read slot. (see Figure 10). By the end of the read time slot, the I/O pin will pull back high via the external
pullup resistor. All read time slots must be a minimum of 60 s in duration with a minimum of a 1 s
recovery time between individual read slots. Figure 11 shows that the sum of t
, t
, and t
must
INIT
RC
SAMPLE
be less than 15 s. Figure 12 shows that system timing margin is maximized by keeping t
, and t
as
INIT
RC
small as possible and by locating the master sample time toward the end of the 15 s period.
RELATED APPLICATIONS NOTES
The following Application Notes can be applied to the DS2437. These notes can be obtained from the
Dallas Semiconductor Application Note Book, via our website at http://www.dalsemi.com, or through our
faxback service at [phone].
Application Note 27: “Understanding and Using Cyclic Redundancy Checks with Dallas Semiconductor
Touch Memory Product”
Application Note 74: “Reading and Writing Touch Memories via Serial Interfaces”
Application Note 110: “NiCd/NiMH Intelligent Battery System Reference Design Using the DS2437”
Sample 1-Wire subroutines that can be used in conjunction with AN74 can be downloaded from the
website.
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