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LTC1695CS5#TRPBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20
LTC1695
1
FEATURES
APPLICATIO S
U
DESCRIPTIO
U
TYPICAL APPLICATION
U
The LTC
®
1695 fan speed controller provides all the func-
tions necessary for a power management microprocessor
to regulate the speed of a 5V brushless DC fan via a 2-wire
SMBus/I
2
C interface. Fan speed is controlled according to
the system’s required temperature profile and permits
lower fan power consumption, longer battery run time and
lower acoustical generated noise versus systems that
only provide simple on-off control for the fan.
The LTC1695 incorporates a 180mA low dropout linear
regulator, a 2-wire SMBus/I
2
C interface and a 6-bit DAC.
Fan speed is controlled by varying the fan’s terminal
voltage through the output voltage of the LTC1695’s linear
regulator. The LTC1695’s output voltage is programmed
by sending a 6-bit digital code to the LTC1695 DAC via the
SMBus. To eliminate fan start-up problems at lower fan
voltages, users can enable the LTC1695’s boost start
feature that provides the DAC’s full-scale output voltage
for 250ms before decreasing to the programmed output
voltage.
The LTC1695 includes output current limiting and thermal
shutdown as well as status monitors that can be read back
by the microprocessor during fault conditions. The
LTC1695 is available in a 5-lead SOT-23 package.
■
Notebook Computers
■
Spot Cooling
■
Portable Instruments
■
Battery-Powered Systems
■
DC Motor Control
■
White LED Power Supplies
■
Programmable Low Dropout Regulator
■
Complete SMBus/I
2
C
TM
Brushless DC Fan Speed
Control System in a 5-Pin SOT-23 package
■
0.75Ω PMOS Linear Regulator with 180mA
Output Current Rating
■
0V to 4.922V Output Voltage Range Controlled by a
6-Bit DAC
■
Simple 2-Wire SMBus/I
2
C Interface
■
250ms Internal Timer Ensures Fan Start-Up
■
Current Limit and Thermal Shutdown
■
Fault Status Indication via SMBus Host Readback
SMBus/I
2
C Fan Speed
Controller in SOT-23
LTC1695
15
2
3
4
V
CC
GND
SCL
V
OUT
SDA
+
SYSTEM
CONTROLLER
+
4.7µF
10µF
5V DC FAN
SUNON
KDE0502PFB2-8
0.6W, 1.7 CFM
(25 • 25 • 10)mm
3
5V
1695 • TA01
Fan Voltage and Current vs DAC Code
DAC CODE
0
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
120
100
80
60
40
20
0
6
5
4
3
2
1
0
30 50
1695 • TA02
10 20
40 60 70
V
CC
= 5V
T
A
= 25°C
I
LOAD
V
OUT
, LTC and LT are registered trademarks of Linear Technology Corporation.
I
2
C is a trademark of Philips Electronics N.V.
LTC1695
2
Terminal Voltages
Supply Voltage (V
CC
) ............................................. 7V
All Other Inputs ........................–0.3V to (V
CC
+ 0.3V)
Operating Temperature Range ..................... 0°C to 70°C
Junction Temperature........................................... 125°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)..................300°C
ORDER PART
NUMBER
S5 PART MARKING
T
JMAX
= 125°C, θ
JA
= 256°C/W
SEE THE APPLICATIONS
INFORMATION SECTION.
Consult factory for Industrial and Military grade parts.
LTIY
LTC1695CS5
ABSOLUTE AXI U RATI GS
W
WW
U
PACKAGE/ORDER I FOR ATIO
UUW
(Note 1)
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V unless otherwise stated.
4 SDA
5 V
OUT
SCL 3
V
CC
1
TOP VIEW
S5 PACKAGE
5-LEAD PLASTIC SOT-23
GND 2
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
CC
Supply Voltage Range 4.5 5 5.5 V
I
CC
Supply Current, Operating V
OUT
= Full Scale, I
LOAD
= 150mA ● 150.7 155 mA
Supply Current, Shutdown DAC Code = 0
● 80 200 µA
DAC
DAC Resolution Guaranteed Monotonic ● 6 Bits
V
LSB
1LSB Resolution I
LOAD
= 1mA ● 73 78 83 mV
V
OS
Offset Error I
LOAD
= 1mA ● ±1 LSB
DNL Differential Nonlinearity I
LOAD
= 1mA (Note 2) ● ±0.75 LSB
INL Integral Nonlinearity I
LOAD
= 1mA (Note 2) ● ±0.75 LSB
V
FS
V
OUT
, DAC Full Scale I
LOAD
= 20mA ● 4.5 4.93 V
I
LOAD
= 150mA ● 4.5 4.9 V
V
ZS
V
OUT
, DAC Zero Scale R
LOAD
= 1kΩ ● 085 mV
R
ON(P)
P-Channel On Resistance I
LOAD
= 150mA 0.75 Ω
Timer and Thermal Shutdown
V
UVLO
Undervoltage Lockout Voltage Rising V
CC
● 2.3 2.9 3.5 V
T
BST_ST
Boost Start Timer I
LOAD
= 10mA, C
LOAD
= 4.7µF ● 75 250 1000 ms
T
THERMAL
Thermal Shutdown Temperature (Note 3) 155 °C
I
FAULT
Output Current Limit Threshold V
OUT
= 0V, DAC Code = 63 ● 180 390 850 mA
SMBus SCL, SDA Inputs
V
IH
Input High Threshold ● 2.1 V
V
IL
Input Low Threshold ● 0.8 V
I
IN
Input Current SCL, SDA = 0V or 5V ● ±0.1 ±5 µA
C
IN
Input Capacitance (Note 3) 3 pF
t
ON
Switch On Time from V
OUT
from Zero Scale to Full Scale, ● 50 500 µs
Stop Condition (f
SMBus
= 100kHz) I
LOAD
= 1mA, C
LOAD
= 4.7µF
t
OFF
Switch Off Time from V
OUT
from Full Scale to Zero Scale, ● 150 500 µs
Stop Condition (f
SMBus
= 100kHz) I
LOAD
= 150mA, C
LOAD
= 4.7µF
V
OL
SDA Output Low Voltage I
PULLUP
= 3mA ● 150 400 mV
LTC1695
3
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V unless otherwise stated.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: INL, DNL specs are specified under a 1mA I
LOAD
condition to keep the
linear regulator from operating in dropout at higher DAC codes. DNL is
measured from code 0 to code 63, taking into account the untrimmed offset
at code 0. Please refer to the Definitions section for more details.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
SMBus TIMING (Note 4)
f
SMB
SMBus Operating Frequency ● 10 100 kHz
t
BUF
Bus Free Time Between Stop and Start ● 4.7 µs
t
HD(STA)
Hold Time After (Repeated) Start Condition ● 4.0 µs
t
SU(STA)
Repeated Start Condition Setup Time ● 4.7 µs
t
SU(STO)
Stop Condition Setup Time ● 4.0 µs
t
HD(DAT)
Data Hold Time ● 300 ns
t
SU(DAT)
Data Setup Time ● 250 ns
t
LOW
Clock Low Period ● 4.7 µs
t
HIGH
Clock High Period ● 4.0 50 µs
t
f
Clock/Data Fall Time ● 300 ns
t
r
Clock/Data Rise Time ● 1000 ns
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Note 3: This typical specification is based on lab measurements and is not
production tested.
Note 4: Guaranteed by design and not tested. Please refer to the Timing
Diagram section for additional information.
DAC CODE
0
OUTPUT VOLTAGE (V)
6
5
4
3
2
1
0
10
20 30 40
1695 • G01
50 60 63
V
CC
= 5V
T
A
= 25°C
I
LOAD
= 1mA
TEMPERATURE (°C)
–50
SUPPLY CURRENT (µA)
250
200
150
100
50
0
0
50
75
1695 • G03
–25
25
100
125
CODE 0
CODE 63
V
CC
= 5V
SUPPLY VOLTAGE (V)
4.0
SUPPLY CURRENT (µA)
6.0
1695 • G02
4.5
5.0
5.5
250
200
150
100
50
0
CODE 0
CODE 63
T
A
= 25°C
Output Voltage vs
DAC Code
No Load Supply Current vs
Temperature
No Load Supply Current vs Supply
Voltage
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LTC1695CS5#TRPBF

Mfr. #:
Buy LTC1695CS5#TRPBF
Manufacturer:
Analog Devices / Linear Technology
Description:
Motor / Motion / Ignition Controllers & Drivers SMBus/I2C Fan Speed Cntr in SOT-23
Lifecycle:
New from this manufacturer.
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