Linear Technology LTC2912ITS8-3, LTC2912 Datasheet

LTC2912

Single UV/OV

Voltage Monitor

FEATURES

■

Monitors Single Voltage

■

Adjustable UV and OV Trip Values

■

Guaranteed Threshold Accuracy: ±1.5%

■

Power Supply Glitch Immunity

■

Adjustable Reset Timeout with Timeout Disable

■

29μA Quiescent Current

■

Open-Drain OV and UV Outputs

■

Guaranteed OV and UV for VCC ≥ 1V

■

Available in 8-Lead ThinSOTTM and (3mm × 2mm)

DFN Packages

APPLICATIONS

■

Desktop and Notebook Computers

■

Network Servers

■

Core, I/O Voltage Monitors

DESCRIPTION

The LTC®2912 voltage monitor is designed to detect power
supply undervoltage and overvoltage events. The VL and
VH monitor inputs include fi ltering to reject brief glitches,
thereby ensuring reliable reset operation without false or
noisy triggering. An adjustable timer defi nes the duration of
the overvoltage and under voltage reset outputs which func­tion independently. While the LTC2912 operates directly
from 2.3V to 6V supplies, an internal V
coupled with low supply current demand allows operation
from higher voltages such as 12V, 24V or 48V.

Three output confi gurations are available: the LTC2912­1 has a latch control for the OV output; the LTC2912-2
has an OV and UV output disable feature for margining
applications; the LTC2912-3 is identical to the LTC2912-1
but with a noninverting, OV output.

The LTC2912 provides a precise, versatile, space-conscious
micropower solution for voltage monitoring.

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.

shunt regulator

CC

TYPICAL APPLICATION

Single OV/UV Supply Monitor, 3.3V ±10% Tolerance Reset Time-Out Period vs Capacitance

POWER
SUPPLY

3.3V

27.4k

1k

4.53k

0.1μF

V

CC

VH

LTC2912-1

VL

LATCH

GND TMR

OV

UV

22nF

SYSTEM

2912 TA01a

TIMEOUT = 200ms

10000

(ms)

1000

UOTO

100

10

UV/OV TIMEOUT PERIOD, t

1

0.1 10 100 1000

1

TMR PIN CAPACITANCE, C

TMR

(nF)

2912 G08

2912fa

1

LTC2912

(

(

(

ABSOLUTE MAXIMUM RATINGS

Terminal Voltages

VCC (Note 3) ............................................. –0.3V to 6V

OV, UV, OV ............................................ –0.3V to 16V

TMR ..........................................–0.3V to (VCC + 0.3V)

VH, VL, LATCH, DIS .............................. –0.3V to 7.5V

Terminal Currents
I
I

....................................................................10mA

VCC

, IOV, IOV ........................................................10mA

UV

(Note 1)

Operating Temperature Range

LTC2912C ................................................ 0°C to 70°C

LTC2912I.............................................. –40°C to 85°C

LTC2912H .......................................... –40°C to 125°C

Storage Temperature Range

TSOT .................................................. –65°C to 125°C

DFN .................................................... –65°C to 150°C

Lead Temperature (Soldering, 10 sec)

TSOT ................................................................. 300°C

PACKAGE/ORDER INFORMATION

TOP VIEW

TOP VIEW

LATCH 1

UV 2
OV 3

GND 4

TS8 PACKAGE

8-LEAD PLASTIC TSOT-23

T

= 150°C, θJA = 195°C/W

JMAX

8 V
7 VH
6 VL
5 TMR

CC

EXPOSED PAD (PIN 9) IS GND, CONNECTION TO PCB OPTIONAL

CC

VH

VL

TMR

3mm × 2mm) PLASTIC DFN

8-LEAD

T

= 150°C, θJA = 76°C/W

JMAX

ORDER PART NUMBER TS8 PART MARKING* ORDER PART NUMBER DDB PART MARKING*

LTC2912CTS8-1
LTC2912ITS8-1
LTC2912HTS8-1

DIS 1

UV 2
OV 3

GND 4

T

JMAX

TOP VIEW

8 V
7 VH
6 VL
5 TMR

TS8 PACKAGE

8-LEAD PLASTIC TSOT-23

= 150°C, θJA = 195°C/W

LTCJW
LTCJW
LTCJW

CC

LTC2912CDDB-1
LTC2912IDDB-1
LTC2912HDDB-1

CC

VH

VL

TMR

3mm × 2mm) PLASTIC DFN

8-LEAD

T

= 150°C, θJA = 76°C/W

EXPOSED PAD (PIN 9) IS GND, CONNECTION TO PCB OPTIONAL

JMAX

ORDER PART NUMBER TS8 PART MARKING* ORDER PART NUMBER DDB PART MARKING*

LTC2912CTS8-2
LTC2912ITS8-2
LTC2912HTS8-2

LATCH 1

GND 4

T

JMAX

TOP VIEW

UV 2
OV 3

TS8 PACKAGE

8-LEAD PLASTIC TSOT-23

= 150°C, θJA = 195°C/W

8 V
7 VH
6 VL
5 TMR

LTCJX
LTCJX
LTCJX

CC

LTC2912CDDB-2
LTC2912IDDB-2
LTC2912HDDB-2

1V

CC

VH

2

VL

3

TMR

4

DDB PACKAGE

3mm × 2mm) PLASTIC DFN

8-LEAD

T

= 150°C, θJA = 76°C/W

EXPOSED PAD (PIN 9) IS GND, CONNECTION TO PCB OPTIONAL

JMAX

ORDER PART NUMBER TS8 PART MARKING* ORDER PART NUMBER DDB PART MARKING*

LTC2912CTS8-3
LTC2912ITS8-3
LTC2912HTS8-3

Order Options

Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/

LTCJY
LTCJY
LTCJY

*The temperature grade is identifi ed by a label on the shipping container.

LTC2912CDDB-3
LTC2912IDDB-3
LTC2912HDDB-3

1V

2

9

3

4

DDB PACKAGE

TOP VIEW

1V

2

9

3

4

DDB PACKAGE

TOP VIEW

9

8

LATCH
UV

7

OV

6

GND

5

LCJZ
LCJZ
LCJZ

8

DIS

UV

7

OV

6

GND

5

LCKB
LCKB
LCKB

8

LATCH
UV

7

OV

6

GND

5

LCKC
LCKC
LCKC

2912fa

2

LTC2912

ELECTRICAL CHARACTERISTICS

The ● denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at TA = 25°C. VCC = 3.3V, VL = 0.45V, VH = 0.55V, LATCH = VCC unless otherwise
noted. (Note 2)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

SHUNT

ΔV

SHUNT

V

CC

V

CCR(MIN)

V

CC(UVLO)

ΔV

CC(UVHYST)

I

CC

V

UOT

t

UOD

VCC Shunt Regulator Voltage ICC = 5mA

–40°C < T

A

VCC Shunt Regulator Load Regulation ICC = 2mA to 10mA

Supply Voltage (Note 3)

Minimum VCC Output Valid DIS = 0V

Supply Undervoltage Lockout DIS = 0V, VCC Rising

Supply Undervoltage Lockout Hysteresis DIS = 0V

Supply Current VCC = 2.3V to 6V

Undervoltage/Overvoltage Threshold

Undervoltage/Overvoltage Threshold to

VHn = V

UOT

Output Delay

I

VHL

t

UOTO

V

LATCH(VIH)

V

LATCH(VIL)

I

LATCH

I

DIS

V

DIS(VIH)

V

DIS(VIL)

I

TMR(UP)

I

TMR(DOWN)

V

TMR(DIS)

V

OH

V

OL

VH, VL Input Current

–40°C < T

UV/OV Time-Out Period C

–40°C < T

TMR

A

= 1nF

A

OV Latch Clear Input High

OV Latch Clear Input Low
LATCH Input Current V

DIS Input Current V

LATCH

> 0.5V

DIS

> 0.5V

DIS Input High

DIS Input Low

TMR Pull-Up Current V

TMR Pull-Down Current V

= 0V

TMR

–40°C < T

= 1.6V

TMR

–40°C < T

A

A

Timer Disable Voltage Referenced to V
Output Voltage High UV/OV/OV VCC = 2.3V, I
Output Voltage Low UV/OV/OV VCC = 2.3V, I

V

= 1V, IUV = 100μA

CC

Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.

Note 2: All currents into pins are positive; all voltages are referenced to
GND unless otherwise noted.

< 125°

– 5mV or VLn = V

UOT

+ 5mV

< 125°

< 125°

< 125°

< 125°

CC

= –1μA

UV/OV

= 2.5mA

UV/OV

Note 3: VCC maximum pin voltage is limited by input current. Since the
V

pin has an internal 6.5V shunt regulator, a low impedance supply that

CC

exceeds 6V may exceed the rated terminal current. Operation from higher
voltage supplies requires a series dropping resistor. See Applications
Information.

●

6.2 6.6 7.2 V

●

6.2 6.6 7.3 V

●

●

2.3 V

●

●

1.9 2 2.1 V

●

52550 mV

●

●

492 500 508 mV

●

50 125 500 μs

●

●

●

6 8.5 12.5 ms

●

6 8.5 14 ms

●

1.2 V

●

●

●

1 2 3.3 μA

●

1.2 V

●

●

–1.3 –2.1 –2.8 μA

●

–1.2 –2.1 –2.8 μA

●

1.3 2.1 2.8 μA

●

1.2 2.1 2.8 μA

●

–180 –270 mV

●

1V

●

●

200 300 mV

SHUNT

1V

29 70 μA

±15 nA

±30 nA

0.8 V

±1 μA

0.8 V

0.10

0.01

0.30

0.15

V

V
V

2912fa

3

LTC2912

)

TIMING DIAGRAMS

VH Monitor Timing

V

VH

UOT

t

UOD

UV

1V

VH Monitor Timing (TMR Pin Strapped to V

V

VH

UOT

t

UOD

UV

1V

t

UOD

t

UOTO

2912 TD01

CC

2912 TD03

)

TYPICAL PERFORMANCE CHARACTERISTICS

Input Threshold Voltage
vs Temperature

0.505

0.504

0.503

(V)

UOT

0.502

0.501

0.500

0.499

0.498

0.497

THRESHOLD VOLTAGE, V

0.496

0.495
–50

–25

TEMPERATURE (°C)

0

25 50

75

100

2912 G01

Supply Current vs Temperature

45

40

VCC = 5V

VCC = 3.3V

VCC = 2.3V

–25 0 25 50

TEMPERATURE (°C)

(μA)

CC

I

35

30

25

20

15

–50

VL Monitor Timing

V

VL

UOT

t

UOD

1V

OV

t

UOTO

2912 TD02

VL Monitor Timing (TMR Pin Strapped to VCC)

V

VL

UOT

t

UOD

OV

1V

t

UOD

2912 TD04

VCC Shunt Voltage
vs Temperature

6.8

10mA

5mA

2mA

1mA

200μA

75 100

2912 G02

(V)

CC

V

6.7

6.6

6.5

6.4

6.3

6.2
–50

02550

–25

TEMPERATURE (°C)

75 100

2912 G03

4

VCC Shunt Voltage vs I

6.75

6.65

6.55

(V)

CC

V

6.45
–40°C

6.35
25°C

85°C

6.25
–2 0

2

Typical Transient Duration vs

CC

6

4

I

CC

8

(mA)

10

12

2912 G04

Comparator Overdrive

700

600

500

400

300

200

100

TYPICAL TRANSIENT DURATION (μs)

VCC = 2.3V

50

0.1

COMPARATOR OVERDRIVE PAST THRESHOLD (%

RESET OCCURS

ABOVE CURVE

VCC = 6V

1 10 100

2912 G05

UV Output Voltage vs V

0.8

0.6

0.4

UV VOLTAGE (V)

0.2

0

0

UV WITHOUT

PULL-UP

0.2
SUPPLY VOLTAGE, V

0.4

V

CC

CC

UV WITH
10k PULL-UP

0.6

CC

(V)

0.8

1

2912 G06

2912fa