Datasheet

ManualsBrandsLINEAR TECHNOLOGY ManualsPMICsPMIC - system monitor Dual voltage detector MSOP 10

LTC2919

2919f

SEL Pin Connection for Input Polarity

Combinations

POLARITY

ADJ1 ADJ2 SEL PIN

+–

OPEN

––

GND

Precision Triple/Dual Input

UV, OV and Negative

Voltage Monitor

■

Desktop and Notebook Computers

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Network Servers

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Core, I/O Monitor

■

Automotive

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Two Low Voltage Adjustable Inputs (0.5V)

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Accurate UVLO Provides a Third Monitor Input

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Open-Drain RST, OUT1 and OUT2 Outputs

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Pin Selectable Input Polarity Allows Negative, UV

and OV Monitoring

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Guaranteed Threshold Accuracy: ±1.5%

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6.5V Shunt Regulator for High Voltage Operation

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Low 50μA Quiescent Current

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Buffered 1V Reference for Negative Supply Offset

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Input Glitch Rejection

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Adjustable Reset Timeout Period

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Selectable Internal Timeout Saves Components

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Outputs Guaranteed Low With V

= 0.5V

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Space Saving 10-Lead 3mm × 2mm DFN and MSOP

Packages

3.3V UV/OV (Window) Monitor Application with

200ms Internal Timeout (3.3V Logic Out)

LTC2919–2.5

ADJ1

ADJ2

REF OUT2

SEL

OUT1

RST

10k

2919 TA01a

453k

3.3V

10.7k

76.8k

0.1µF

TMR

GND

FAULT

The LTC

2919 is a triple/dual input monitor intended for a

variety of system monitoring applications. Polarity selec-

tion and a buffered reference output allow the LTC2919 to

monitor positive and negative supplies for undervoltage

(UV) and overvoltage (OV) conditions.

The two adjustable inputs have a nominal 0.5V threshold,

featuring tight 1.5% threshold accuracy over the entire

operating temperature range. Glitch ﬁ ltering ensures out-

puts operate reliably without false triggering. An accurate

threshold at the V

pin provides a third input supply

monitor for a 2.5V, 3.3V or 5V supply.

Two independent output pins indicate the status of each

adjustable input. A third common output provides a

conﬁ gurable reset timeout that may be set by an accu-

rate internal 200ms timer, programmed with an external

capacitor, or disabled for a fast response. A three-state

input pin sets the input polarity of each adjustable input

without requiring any external components.

The LTC2919 provides a highly versatile, precise, space-

conscious, micropower solution for supply monitoring.

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners. Protected by U.S. Patents,

including 6949965, 7292076.

Summary of content (16 pages)

PAGE 1
LTC2919 Precision Triple/Dual Input UV, OV and Negative Voltage Monitor U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Two Low Voltage Adjustable Inputs (0.5V) Accurate UVLO Provides a Third Monitor Input Open-Drain RST, OUT1 and OUT2 Outputs Pin Selectable Input Polarity Allows Negative, UV and OV Monitoring Guaranteed Threshold Accuracy: ±1.5% 6.
PAGE 2
LTC2919 W W U W ABSOLUTE AXI U RATI GS (Notes 1, 2) Terminal Voltages VCC (Note 3)............................................. –0.3V to 6V OUT1, OUT2, RST ................................. –0.3V to 7.5V ADJ1, ADJ2 .......................................... –0.3V to 7.5V TMR, SEL..................................–0.3V to (VCC + 0.3V) Terminal Currents ICC (Note 3)......................................................±10mA IREF ....................................................................
PAGE 3
LTC2919 ELECTRICAL CHARACTERISTICS The ● denotes the speciﬁcations which apply over the full operating temperature range, otherwise speciﬁcations are at TA = 25°C. VCC = 2.5V (LTC2919-2.5), VCC = 3.3V (LTC2919-3.3), VCC = 5V (LTC2919-5), ADJ1 = ADJ2 = 0.55V, SEL = ﬂoating, unless otherwise noted. (Note 2) SYMBOL PARAMETER CONDITIONS VCC(MIN) Operating Supply Voltage RST, OUT1, OUT2 in Correct State ● MIN 0.5 VCC(SHUNT) VCC Shunt Regulation Voltage ICC = 1mA, IREF = 0 ● 6.
PAGE 4
LTC2919 ELECTRICAL CHARACTERISTICS The ● denotes the speciﬁcations which apply over the full operating temperature range, otherwise speciﬁcations are at TA = 25°C. VCC = 2.5V (LTC2919-2.5), VCC = 3.3V (LTC2919-3.3), VCC = 5V (LTC2919-5), ADJ1 = ADJ2 = 0.55V, SEL = ﬂoating, unless otherwise noted.
PAGE 5
LTC2919 U W TYPICAL PERFOR A CE CHARACTERISTICS Reset Timeout Period vs Capacitance Propagation Delay vs Overdrive 700 260 400 300 200 RESET TIMEOUT PERIOD, tRST (ms) RESET TIMEOUT PERIOD, tRST (ms) 1000 0 0.1 1 10 100 GLITCH PERCENTAGE PAST THRESHOLD (%) 100 10 1 0.1 1 10 100 TMR PIN CAPACITANCE, CTMR (nF) Shunt Regulation Voltage vs Temperature ICC = 10mA 6.6 ICC = 1mA 6.4 ICC = 100μA 6.2 25 50 75 100 125 150 TEMPERATURE (°C) 7.6 6.8 6.4 WITH 10k PULL-UP 0.1 WITH 100k PULL-UP 0.2 0.3 0.
PAGE 6
LTC2919 U W TYPICAL PERFOR A CE CHARACTERISTICS OUT1, OUT2, RST VOL vs Output Sink Current ISEL vs Temperature –10 1.0 VCC = 3V NO PULL-UP R SEL = GND –12 20 TA = 25°C –14 18 TA = 125°C 0.4 TA = –40°C 0.2 0 5 15 20 25 10 OUTPUT SINK CURRENT (mA) 30 ISEL (μA) 0.6 0 ISEL vs Temperature 22 SEL = VCC TA = 150°C ISEL (μA) OUTPUT, VOL (V) 0.8 TA = 25°C unless otherwise noted.
PAGE 7
LTC2919 U U U PI FU CTIO S (MSOP/DFN Package) Exposed Pad (Pin 11, DFN Only): The Exposed Pad may be left unconnected. For better thermal contact, tie to a PCB trace. This trace must be grounded or unconnected. ADJ1 (Pin 10): Adjustable Voltage Input 1. Input to voltage monitor comparator 1 (0.5V nominal threshold). The polarity of the input is selected by the state of the SEL pin (refer to Table 1). Tie to REF if unused (with SEL = VCC or Open).
PAGE 8
LTC2919 U W U U APPLICATIO S I FOR ATIO The LTC2919 is a low power, high accuracy triple/dual supply monitor with two adjustable inputs and an accurate UVLO that can monitor a third supply. Reset timeout may be selected with an external capacitor, set to an internally generated 200ms, or disabled entirely. The three-state polarity select pin (SEL) chooses one of three possible polarity combinations for the adjustable input thresholds, as described in Table 1.
PAGE 9
LTC2919 U U W U APPLICATIO S I FOR ATIO If the user’s application requires, the SEL pin may be driven using a three-state buffer which satisﬁes the VIL, VIH and leakage conditions of this three-state input pin. If the state of the SEL pin conﬁgures a given input as “negative polarity,” the voltage at that ADJ pin must be below the trip point (0.5V nominal), or the corresponding OUT and RST output will be pulled low.
PAGE 10
LTC2919 U U W U APPLICATIO S I FOR ATIO Table 2b. Possible Combinations of Supply Monitoring. For Example Purposes, All Supplies are Monitored at 5% Tolerance and Connections are Shown Only for ADJ1, ADJ2, REF, SEL, OUT1 and OUT2. Output Pull-up Resistors are Omitted for Clarity. SEL OPEN 15V –15V RP6 2.37M RN6 1.02M RP5 10.7k ADJ1 OUT1 UV ADJ2 OUT2 OV RN5 4.02k RP4 76.8k SEL –15V –15V RN2 1.02M ADJ1 OUT1 UV (15V) ADJ2 OUT2 UV (–15V) RN1 10.7k RN1 30.9k REF 15V RP1A 11.
PAGE 11
LTC2919 U W U U APPLICATIO S I FOR ATIO 4.425V ±75mV over temperature (i.e., 10% to 13% below 5V). The monitored system must thus operate reliably down to 4.35V or 13% below 5V over temperature. The above discussion is concerned only with the DC value of the monitored supply. Real supplies also have relatively high frequency variations from sources such as load transients, noise and pickup. The LTC2919 uses two techniques to combat spurious outputs toggling from high frequency variation.
PAGE 12
LTC2919 U W U U APPLICATIO S I FOR ATIO To minimize errors arising from ADJ input bias and to minimize loading on REF choose resistor RP1 (for positive supply monitoring) or RN1 (for negative supply monitoring) in the range of 5k to 100k. For a positive-monitoring application, RP2 is then chosen by: REF ADJ1 + RN4 RN5 – ADJ2 + RN6 RP2 = RP1(2VTRIP – 1) – –VMON For a negative-monitoring application: 0.5V The LTC2919 can also be used to monitor a single supply for both UV and OV.
PAGE 13
LTC2919 U W U U APPLICATIO S I FOR ATIO If the user wishes to avoid having an external capacitor, the TMR pin should be tied to ground, switching the part to an internal 200ms timer. If the user requires a shorter timeout than 400μs, or wishes to perform application-speciﬁc processing of the reset output, the part may be put in comparator mode by tying the TMR pin to VCC. In comparator mode, the timer is bypassed and comparator outputs go straight to the reset output.
PAGE 14
LTC2919 U TYPICAL APPLICATIO S Six Supply Undervoltage Monitor with 2.5V Reset Output and 20ms Timeout 15V 5V –5V –15V 3.3V 2.5V SYSTEM CBYP1 100nF RPU1 10k RPU5 10k RPU2 10k RN2A 137k RN1A 13.3k SYSTEM_OK SEL LTC2919-2.5 ADJ2 TMR OUT1 OUT2 GND ADJ1 RP1A 13.7k LTC2919-3.3 RST REF RP2A 115k VCC SEL RN1B 10.7k CTMR1 2.2nF RPU3 10k VCC ADJ1 RN2B 309k CBYP2 100nF RPU4 10k RST –5V_OK 5V_OK –15V_OK 15V_OK RP2B 309k REF RP1B 11.5k OUT1 ADJ2 2919 TA02 OUT2 TMR GND CTMR2 2.
PAGE 15
LTC2919 U PACKAGE DESCRIPTIO DDB Package 10-Lead Plastic DFN (3mm × 2mm) (Reference LTC DWG # 05-08-1722 Rev Ø) 0.64 ±0.05 (2 SIDES) 3.00 ±0.10 (2 SIDES) R = 0.05 TYP R = 0.115 TYP 6 0.40 ± 0.10 10 0.70 ±0.05 2.55 ±0.05 1.15 ±0.05 PACKAGE OUTLINE 0.25 ± 0.05 2.00 ±0.10 (2 SIDES) PIN 1 BAR TOP MARK (SEE NOTE 6) 0.75 ±0.05 0.200 REF 0.50 BSC 2.39 ±0.05 (2 SIDES) 0.64 ± 0.05 (2 SIDES) 5 0.25 ± 0.05 1 (DDB10) DFN 0905 REV Ø 0.50 BSC 2.39 ±0.05 (2 SIDES) 0 – 0.
PAGE 16
LTC2919 U TYPICAL APPLICATIO Powered from 12V, +5VOUT is Sequenced to Start-up First, Followed by –5VOUT, with ±5V UV Monitor, 200ms Timeout +12V RCC 4.7k CBYP 0.1μF DC/DC CONVERTER +5V VCC RP2 115k LTC2919-2.5 ADJ1 RP1 13.7k RN2 –5V 137k DC/DC CONVERTER +5V SEL REF OUT2 RPU2 10k PWRGD RN1 13.3k SHDN RST ADJ2 TMR OUT1 GND RPU3 10k SYS_RESET 2919 TA06 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC1326/LTC1326-2.5 Micropower Precision Triple Supply Monitor for 5V/2.5V, 3.