LTC1840CGN Linear Technology, LTC1840CGN Datasheet

IC DUAL FAN CONTROLLER 16-SSOP

LTC1840CGN

Manufacturer Part Number
LTC1840CGN
Description
IC DUAL FAN CONTROLLER 16-SSOP
Manufacturer
Linear Technology
Datasheet

Specifications of LTC1840CGN

Applications
Fan Controller
Number Of Outputs
2
Current - Output
10mA
Voltage - Supply
2.7 V ~ 5.75 V
Operating Temperature
0°C ~ 70°C
Mounting Type
Surface Mount
Package / Case
16-SSOP
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Voltage - Load
-

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LTC1840CGN
Manufacturer:
LT
Quantity:
10 000
Part Number:
LTC1840CGN#PBF
Manufacturer:
LINEAR/凌特
Quantity:
20 000
FEATURES
APPLICATIO S
I
TYPICAL APPLICATIO
2
C is a trademark of Philips Electronics N.V.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Two 8-Bit Current DACs
DACs Guaranteed Monotonic
Known IC State on Power-Up
Serial Interface Watchdog Timer with Disable
2-Wire Serial Interface Compatible with I
and SMBus
2 Programmable Fan Tachometer Interfaces
4 Programmable General Purpose I/Os
Small 16-Pin SSOP Package
Single 2.7V to 5.75V Supply Operation
Fault Output Signal
Status Register
Fan Blasting Function
Nine Addresses Using Two Programming Lines
Servers
Desktop Computers
Power Supplies
Cooling Systems
LED2
130
3.3V
MASTER
LED1
130
ADDRESS = 1110010
(8 OTHERS POSSIBLE)
U
TO
3.3V
10k
NC
NC
3.3V
FAULT
SDA
SCL
A0
A1
GPI01
GPI02
LTC1840
GND
3.3V
V
CC
IDACOUTA
IDACOUTB
BLAST
TACHB
TACHA
GPI04
GPI03
U
+
SYSTEM
RESET
Low Parts Count, High Efficiency Dual Fan Control
10 F
2
C
R
10k
R
10k
C1
C
220pF
C2
C
220pF
TM
C1
C2
0.1 F
C
100pF
C
100pF
FB1
FB2
RUN/SS
I
V
RUN/SS
I
V
TH
TH
12V
12V
FB
FB
DESCRIPTIO
LTC1771
LTC1771
The LTC
output DACs, two tachometer interfaces, and four general
purpose I/O (GPIO) pins. It operates from a single supply
with a range of 2.7V to 5.75V. A current output DAC is used
to control an external switching regulator, which controls
the fan speed. A current output DAC and tachometer allow
a controller to form a closed control loop on fan velocity.
The GPIO pins can be used as digital inputs or open drain
pull-down outputs.
The part features a simple 2-wire I
ible serial interface that allows communication between
many devices. The interface includes a fault status register
that reflects the state of the part and which can be polled
to find the cause of a fault condition. Other operational
characteristics of the part, such as DAC output currents,
GPIO modes, and tachometer frequency, are also pro-
grammed through the serial interface. Two address pins
provide nine possible device addresses.
The BLAST pin is provided to force the DAC output
currents to program the maximum regulator output
voltages through a single pin and gate the operation of the
serial access timer.
GND
GND
V
V
IN
IN
SENSE
SENSE
PGATE
PGATE
MODE
MODE
R
R
SENSE1
SENSE2
®
0.05
0.05
1840 is a fan controller with two 8-bit current
with 2-Wire Interface
Si6447DQ
Si6447DQ
UPS5817
UPS5817
L1 47 H
L2 47 H
+
+
Dual Fan Controller
C
22 F
C
22 F
VIN1
VIN2
U
2-NMB 6820PL-04W-B29-D50 FANS
1.1A NOM AT 12V
R
75k
R
28k
R
75k
R
28k
FB1A
FB1B
FB2A
FB2B
+
+
C
150 F
C
150 F
OUT1
OUT2
2
FAN
FAN
DC
DC
C and SMBus compat-
TACH
TACH
OUT
OUT
10k
LTC1840
1840 TA01
10k
3.3V
3.3V
1
1840f

Related parts for LTC1840CGN

LTC1840CGN Summary of contents

Page 1

... Single 2.7V to 5.75V Supply Operation Fault Output Signal Status Register Fan Blasting Function Nine Addresses Using Two Programming Lines U APPLICATIO S Servers Desktop Computers Power Supplies Cooling Systems , LTC and LT are registered trademarks of Linear Technology Corporation trademark of Philips Electronics N.V. U TYPICAL APPLICATIO 3.3V 3.3V 10k V CC ...

Page 2

... A0 and A1 Floating CC (Note 2) 2.7V < V < 5.75V 0.7V, Internal Pull-Down Enabled GPIOX Internal Pull-Down Disabled Internal Pull-Down Disabled (Note 2) Internal Pull-Down Disabled U W ORDER PART TOP VIEW NUMBER LTC1840CGN DACOUTA LTC1840IGN DACOUTB 4 13 BLAST 5 12 TACHB 6 11 TACHA GN PART 7 10 GPIO4 ...

Page 3

ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER Digital Inputs SCL, SDA V Digital Input High Voltage IH V Digital Input Low Voltage IL V Logic Threshold Voltage LTH I Digital Input Leakage LEAK C Digital Input ...

Page 4

LTC1840 W U TYPICAL PERFOR A CE CHARACTERISTICS Supply Current vs Supply Voltage 550 500 450 400 2.5 3.5 4.5 5.5 6.5 V (V) CC 1840 G01 DACOUT DACOUT at V ...

Page 5

W U TYPICAL PERFOR A CE CHARACTERISTICS DAC INL 0 0.3 0.2 0.1 0 –0.1 –0.2 0 CODE CTIO S SCL (Pin 1): Serial Clock ...

Page 6

LTC1840 CTIO S BLAST (Pin 13): Blast/Timer Function Input. This is a multifunction digital input pin that controls blast and timer operation. If this pin logic high state at power- ...

Page 7

U OPERATIO SDA SCL 1 START ADDRESS R/W CONDITION Serial Interface Simple 2-wire interface Multiple devices on same bus Idle bus must have SDA and SCL lines high LTC1840 is read/write Master controls bus Devices listen for unique ...

Page 8

LTC1840 U OPERATIO LTC1840 Device Addressing It is possible to configure the part to operate with any one of nine separate addresses through the three state A0 and A1 pins. Table 1 shows the correspondence of addresses to the states ...

Page 9

U OPERATIO DIV1 and DIV0 program the ratio by which the internal 50kHz oscillator frequency is divided down to produce the tachometer clocks ( 16). The DIV bits power-up low, which corresponds to a frequency division of ...

Page 10

LTC1840 U OPERATIO GPIO Operation The GPIO circuits feature N-channel MOSFET open drain pull-downs that can drive LEDs and readback circuitry to allow the logic states of the GPIO pins to be accessed through the serial interface. The circuits that ...

Page 11

... FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...

Page 12

... SMBus Accelerator LTC1771 Ultralow Supply Current Step-Down DC/DC Controller LTC4300-1 Hot Swappable 2-Wire Bus Buffer No R and ThinSOT are trademarks of Linear Technology Corporation. SENSE Linear Technology Corporation 12 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 Controlling Fan Pair with Automatic Blast Redundancy ...

Related keywords