OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

LTC1921IS8#TRPBF

P1-P3P4-P6P7-P9P10-P12
LTC1921
1
1921f
Dual –48V Supply
and Fuse Monitor
, LTC and LT are registered trademarks of Linear Technology Corporation.
The LTC
®
1921 monitors two independent –48V supplies,
including their fuses, and drives up to three optoisolators
to indicate status, in accordance with standard backplane
specifications. Requiring only three noncritical resistors
and optoisolators, the LTC1921 replaces multiple voltage
comparators, a voltage reference and several precision
resistors.
The monitor features dual supply overvoltage and under-
voltage detection circuits. The preset trip thresholds in-
clude overvoltage, undervoltage and undervoltage recovery
that are guaranteed over temperature and meet or exceed
common backplane specifications. Additional built-in cir-
cuitry detects the condition of supply fuses. Overvoltage
and undervoltage detectors ignore fast supply transients,
eliminating false detection. The LTC1921 operates from
–10V to –80V with a typical power dissipation of less than
10mW.
The LTC1921 is available in 8-pin MSOP and SOIC pack-
ages.
■
Withstands Transient Voltages Up to 200V/–200V
■
Requires No Precision External Components
■
Independently Monitors Two –48V Supplies for
– Undervoltage Faults: –38.5V ±1V
MAX
– Overvoltage Faults: –70V ±1.5V
MAX
■
Accurately Detects Undervoltage Fault Recovery:
–43V ±0.5V
MAX
■
Monitors Two External Fuses
■
Operates from –10V to –80V
■
Tolerates DC Faults to –100V
■
Tolerates Accidental Supply Reversal to 100V
■
Small Footprint: 8-Lead MSOP Package
■
Specified from –40°C to 85°C
■
Telecom Backplanes or Switch Cards
■
Networking Backplanes or Switch Cards
■
High Voltage Fuse Monitoring
FEATURES
APPLICATIO S
U
DESCRIPTIO
U
TYPICAL APPLICATIO
U
FUSE GOOD
SUPPLY A GOOD
MOC207
MOC207
MOC207
1921 TA01
SUPERVISOR
µP
LOGIC
SUPPLY
LOGIC
COMMON
47k
47k 47k
R3
47k
1/4W
SUPPLY B GOOD
OUT FV
A
3
4
57
2
8
1
6
V
B
FUSE A
RTN
LTC1921
FUSE B
OUT A
OUT B
D1 MURS320
F1
SUPPLY A
–48V
SUPPLY B
–48V
F2
D2 MURS320
R1
100k
–48V
RETURN
R2
100k
–48V LOAD
LTC1921
2
1921f
ABSOLUTE AXI U RATI GS
W
WW
U
PACKAGE/ORDER I FOR ATIO
UUW
(Note 1) All voltages referred to RTN
Supply Voltage
(V
A
, V
B
, FUSE A, FUSE B) ....................... 100V to –100V
Transient Voltage (V
A
, V
B
, FUSE A, FUSE B)
(Note 2) ........................................................ 0V to 200V
Transient Voltage (V
A
, V
B
, FUSE A, FUSE B)
(Note 2) ......................................................0V to –200V
OUT A, OUT B, OUT F Pins ......................... 0.3V to –8V
ORDER PART
NUMBER
LTC1921CMS8
LTC1921IMS8
T
JMAX
= 150°C, θ
JA
= 300°C/W
MS8 PART MARKING
LTZV
LTZU
Consult LTC Marketing for parts specified with wider operating temperature ranges.
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 5) RTN = 0V, V
A
= –48V, V
B
= –48V, FUSE A = –48V,
FUSE B = –48V, unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNITS
Power Supply
Supply Voltage Range (RTN – V
A
, RTN –␣ V
B
) ● 10 80 V
Supply Current (I
A
+ I
B
) –160 –250 µA
● –300 µA
Supply Monitor
Undervoltage Threshold ● –39.5 –37.5 V
Undervoltage Recovery Threshold ● –43.5 –42.5 V
Overvoltage Threshold ● –71.5 –68.5 V
Overvoltage Threshold Hysteresis ● 1 1.6 V
Fuse Monitor
Input Resistance, FUSE A, FUSE B 11 MΩ
Fuse Comparison Threshold |V
FUSEA
– V
A
|, |V
FUSEB
– V
B
| V
LTC1921C ● 0.9 4.5 V
LTC1921I
● 0.5 4.5 V
Output
Propagation Delay C
OUT
= 100pF, Overdrive = 1V 220 µs
Output Switch Resistance, OUT F, OUT A, OUT B V
A
= V
B
= –35V, V
FUSEA
= V
FUSEB
= 0V 25 Ω
I
OUT
= 10mA ● 50 Ω
Maximum Junction Temperature ......................... 150°C
Operating Temperature Range (Note 3)
LTC1921C/LTC1921I .......................... –40°C to 85°C
Specified Temperature Range (Note 4)
LTC1921C/LTC1921I .......................... –40°C to 85°C
Storage Temperature Range ................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)..................300°C
ORDER PART
NUMBER
LTC1921CS8
LTC1921IS8
S8 PART MARKING
1921
1921I
ELECTRICAL CHARACTERISTICS
1
2
3
4
V
A
FUSE A
RTN
OUT F
8
7
6
5
V
B
FUSE B
OUT B
OUT A
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
1
2
3
4
8
7
6
5
TOP VIEW
V
B
FUSE B
OUT B
OUT A
V
A
FUSE A
RTN
OUT F
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C, θ
JA
= 190°C/W
LTC1921
3
1921f
Supply Current vs Supply Voltage
Undervoltage Threshold
vs TemperatureSupply Current vs Temperature
Undervoltage Recovery Threshold
vs Temperature
Overvoltage Threshold
vs Temperature
Overvoltage Hysteresis
vs Temperature
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Transient voltage for less than 10µs. This parameter is not 100%
tested. Voltage should not exceed 200V between any two pins.
Note 3: The LTC1921C and LTC1921I are guaranteed functional over the
operating temperature range of –40°C to 85°C.
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 5) RTN = 0V, V
A
= –48V, V
B
= –48V, FUSE A = –48V,
FUSE B = –48V, unless otherwise noted.
Note 4: The LTC1921C is guaranteed to meet specified performance from
0°C to 70°C. The LTC1921C is designed, characterized and expected to
meet specified performance from –40°C to 85°C but is not tested or QA
sampled at these temperatures. The LTC1921I is guaranteed to meet
specified performance from –40 t0 85°C.
Note 5: All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to RTN unless otherwise
specified.
PARAMETER CONDITIONS MIN TYP MAX UNITS
Output Switch Off Leakage 500 pA
Output Switch Resistance in Undervoltage Lockout, V
A
= V
B
= –10V, I
OUT
= 10mA ● 60 Ω
OUT F, OUT A, OUT B V
A
= –10V, V
B
= 0V, I
OUT
= 10mA ● 80 Ω
V
A
= 0V, V
B
= –10V, I
OUT
= 10mA ● 80 Ω
ELECTRICAL CHARACTERISTICS
TYPICAL PERFOR A CE CHARACTERISTICS
UW
SUPPLY VOLTAGE (V)
0
SUPPLY CURRENT (µA)
400
350
300
250
200
150
100
50
0
80
1921 G01
20 40 60 1007010 30 50 90
V
A
= V
B
= V
FUSEA
= V
FUSEB
TEMPERATURE (°C)
–50
SUPPLY CURRENT (µA)
100
I
A
+ I
B
I
A
, I
B
120
140
90
1921 G02
80
60
0
–30 –10 10 30 50 70
40
20
180
160
V
A
= –48V
V
B
= –48V
V
FUSEA
= –48V
V
FUSEB
= –48V
TEMPERATURE (°C)
UNDERVOLTAGE THRESHOLD (V)
1921 G04
–37.5
–37.7
–37.9
–38.1
–38.3
–38.5
–38.7
–38.9
–39.1
–39.3
–39.5
–50 –30 –10 10
30 50 70
90
TEMPERATURE (°C)
–50 –30 –10 10
UNDERVOLTAGE RECOVERY THRESHOLD (V)
30 50 70
90
1921 G04
–42.5
–42.6
–42.7
–42.8
–42.9
–43.0
–43.1
–43.2
–43.3
–43.4
–43.5
TEMPERATURE (°C)
OVERVOLTAGE THRESHOLD (V)
1921 G05
–68.0
–68.5
–69.0
–69.5
–70.0
–70.5
–71.0
–71.5
–72.0
–50 –30 –10 10
30 50 70
90
TEMPERATURE (°C)
OVERVOLTAGE HYSTERESIS (V)
1921 G06
1.50
1.45
1.40
1.35
1.30
1.25
1.20
1.15
1.10
1.05
1.00
–50 –30 –10 10
30 50 70
90
P1-P3P4-P6P7-P9P10-P12

LTC1921IS8#TRPBF

Mfr. #:
Buy LTC1921IS8#TRPBF
Manufacturer:
Analog Devices Inc.
Description:
Current & Power Monitors & Regulators 2x -48V S & Fuse Mon
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet