MAX6651EEE Maxim Integrated Products, MAX6651EEE Datasheet - Page 11

• Manufacturer Part Number: MAX6651EEE
• Description: IC REG/MONITOR FAN-SPEED 16-QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX6651EEE

• Applications: Fan Controller, Brushless (BLDC)
• Number Of Outputs: 1
• Voltage - Load: 0.3 V ~ 5.2 V
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Operating Supply Voltage: 3 V to 5.5 V
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: Q1113225

Table 5. GPIO Definition Register
Table 6. GPIO Status Register
Alarm Status Register if the condition that caused the
alarm is removed.
The Tachometer Count Registers record the number of
pulses on the corresponding tachometer input during the
period defined by the Tachometer Count-Time Register.
BIT
7 (MSB) to 5
5:4
3:2
1:0
7
6
0 (LSB)
BIT
4
3
2
1
(DEFAULT)
STATE
POR
11
11
11
1
1
GPIO4 (MAX6651 only)
GPIO3 (MAX6651 only)
GPIO2 (MAX6651 only)
______________________________________________________________________________________
(must be 11)
(must be 1)
(must be 1)
MAX6650
Always 0
GPIO1
GPIO0
NAME
with SMBus/I
GPIO1
GPIO0
PIN
N/A
N/A
N/A
Fan-Speed Regulators and Monitors
MAX6651
GPIO4
GPIO3
GPIO2
GPIO1
GPIO0
Tachometer
PIN
(DEFAULT
STATE)
POR
0
1
1
1
1
1
STATE
00
01
10
11
00
01
10
11
00
01
10
11
0
1
0
1
2
C-Compatible Interface
The MAX6651 contains three additional tachometer
inputs, which may be used to monitor additional fans. For
accurate control of multiple fans, use identical fans.
The Tachometer Count-Time Register sets the integration
time over which the MAX6650/MAX6651 count tachome-
ter pulses. The devices can count up to 255 (FFh) pulses
during the selected count time. If more than 255 pulses
occur, the IC sets the overflow alarm and the Tachometer
Count Register reports the maximum value of 255. Set
the time register so the count register will not overflow
under worst-case conditions (maximum fan speed) while
maximizing resolution. Calculate the maximum measur-
able fan speed and minimum resolution with the following
equations:
where t
maximum allowable tachometer input frequency for the
MAX6650/MAX6651.
GPIO4 outputs a logic-low level.
GPIO4 outputs a logic-high level or serves as an input.
GPIO3 outputs a logic-low level.
GPIO3 outputs a logic-high level or serves as an input.
GPIO2 serves as an external clock input.
GPIO2 serves as an internal clock output.
GPIO2 outputs a logic-low level.
GPIO2 outputs a logic-high level or serves as an input.
GPIO1 outputs a logic-high level or serves as an input.
GPIO1 serves as a FULL ON input.
GPIO1 outputs a logic-low level.
GPIO1 outputs a logic-high level or serves as an input.
GPIO0 outputs a logic-high level or serves as an input.
GPIO0 serves as an ALERT output.
GPIO0 outputs a logic-low level.
GPIO0 outputs a logic-high level or serves as an input.
Max Fan Speed (in RPS) = 255 / (2 x t
Min Resolution (in RPS) = 1 / (2 x t
COUNT
is the tachometer count time; 1kHz is the
FUNCTION
COUNT
COUNT
)
)
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