Datasheet

LTC2991
26
2991fd
For more information www.linear.com/LTC2991
Typical applicaTions
Battery Monitoring
Wet Bulb Psychrometer
REFERENCES
http://en.wikipedia.org/wiki/Hygrometer
http://en.wikipedia.org/wiki/Psychrometrics
V
CC
V1
LTC2991
5V
µC
GND
T
DRY
T
WET
MMBT3904 MMBT3904
SDA
SCL
ADR0
ADR1
ADR2
V3
V4
V2
2991 TA08
470pF
T
AMBIENT
DAMP MUSLIN
WATER
RESERVOIR
CONTROL REGISTER 0x06 = 0xAA
T
AMBIENT
REG 1A, 1B: 0.0625°C/LSB
T
WET
REG 0A, 0B: 0.0625°C/LSB
T
DRY
REG 0C, 0D: 0.0625°C/LSB
V
CC
REG 1C, 1D: 2.5V + 305.18µV/LSB
∆T
NDS351AN
FAN ENABLE
5V
FAN
FAN: SUNON
KDE0504PFB2
OTHER APPS
V5 TO V8
4
V
CC
V1
LTC2991
BATTERY I AND V MONITOR
0.1Ω*
CHARGING
CURRENT
2-WIRE I
2
C
INTERFACE
5V
GND
NiMH
BATTERY
V(t)
100% 100%
• • •
T
BATT
MMBT3904
SDA
SCL
ADR0
ADR1
ADR2
V3
V4
V2
2991 TA07
T
AMBIENT
*IRC LRF3W01R015F
VOLTAGE AND TEMPERATURE CONFIGURATION:
CONTROL REGISTER: 0xA1
T
AMBIENT
REG 1A, 1B: 0.0625°C/LSB
V
BAT
REG 0A, 0B: 305.18µV/LSB
I
BAT
REG 0C, 0D: 190.75µA/LSB
T
BAT
REG 0E, 0F: 0.0625°C/LSB
V
CC
REG 1C, 1D: 2.5V + 305.18µV/LSB
+
T(t)
100%
I(t)
OTHER APPS
V5 TO V8
4