MAX6900 Maxim, MAX6900 Datasheet - Page 4

• Manufacturer Part Number: MAX6900
• Description: I2C-Compatible RTC in a TDFN
• Manufacturer: Maxim

Figure 1. Detailed
I
(T
4
2
A
= +25°C, unless otherwise noted.)
_______________________________________________________________________________________
C-Compatible RTC in a TDFN
PIN
—
PROTOCOL
SCL
SDA
1
2
3
4
5
6
NAME
GND
SDA
PAD
V
SCL
I
X1
X2
t
2 C-Bus Timing Diagrams
CC
HD:STA
t
SU:STA
t
BUF
CONDITION
START
(S)
Power Supply
32.768kHz External Crystal
32.768kHz External Crystal
Ground
I
I
Input/Output
Ground
2
2
C-Bus-Compatible Clock Input
C-Bus-Compatible Data
Pin Description
t
t
LOW
r
FUNCTION
BIT 7
MSB
(A7)
t
HIGH
t
HD:DAT
1.6
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
1.0
1.5
TIMEKEEPING CURRENT vs. V
t
f
2.0 2.5 3.0
1/f
BIT 6
(A6)
SCL
V
CC
3.5 4.0 4.5
(V)
The MAX6900 contains eight timekeeping registers,
burst address registers, a control register, an on-chip
32.768kHz oscillator circuit, and a serial 2-wire, I
compatible interface. There are also 31 bytes, 8 bits
wide of SRAM on board. Time and calendar data are
stored in the registers in a binary-coded decimal (BCD)
format. Figure 1 shows an I
diagram. Figure 2 shows the MAX6900 functional dia-
gram.
The RTC provides seconds, minutes, hours, day, date,
month, and year information. The end of the month is
automatically adjusted for months with fewer than 31
Typical Operating Characteristics
t
HD:DAT
5.0
CC
5.5
6.0
(R/W)
BIT 0
LSB
ACKNOWLEDGE
Detailed Description
(A)
2
C-bus-compatible timing
t
Real-Time Clock
SU:STO
CONDITION
STOP
(P)
2
C-