Voltage Monitors & Supervisors Quick Guide

Voltage Monitors & Supervisors Quick Guide
Linear Technology’s voltage monitors and supervisors monitor positive and negative power supplies ranging from 0.5V
to 48V, with integration of up to eight supply monitors in a tiny package. Not all supervisors are created equal. Look for
the following important features.
5V
NOMINAL
SUPPLY
VOLTAGE
SUPPLY TOLERANCE
MINIMUM
RELIABLE
SYSTEM
VOLTAGE
IDEAL
SUPERVISOR
THRESHOLD
4.75V
±1.5%
THRESHOLD
BAND
–5%
4.675V
1.5% Guaranteed Threshold Accuracy
For a 5V system with ±5% tolerance, the supply may vary between 4.75V to
5.25V, requiring a perfectly accurate supervisor to generate a reset at exactly
4.75V. However, the actual reset threshold of a supervisor varies over a specified
band. The actual reset threshold accuracy of most Linear Technology supervisors
is ±1.5% around the nominal threshold voltage (i.e., 4.675V), minimizing the
required system voltage margin and probability of system malfunction.
–6.5%
4.6V
–8%
Voltage Threshold Settings
REGION OF POTENTIAL MALFUNCTION
Adjustable/Pin-Selectable Thresholds and Tolerances
Adjustable and pin-selectable thresholds provide users with maximum
flexibility, allowing a single part to be used across multiple designs.
No need to hassle with factory-trimmed thresholds and tolerances or
the procurement of multiple parts. Linear Technology supervisors with
adjustable inputs (ADJ) allow selection of virtually any voltage using
external resistors. And supervisors with pin-selectable thresholds and
tolerances possess the most common supply voltage thresholds
(or threshold combinations) and tolerances without the need for
precision external resistors.
VCC
5V
VCC
Open
3.3V
VCC
GND
2.5V
Open
VCC
1.8V
Open
Open
1.5V
Open
GND
1.2V
GND
VCC
1V
GND
ADJ (0.5V)
GND
SEL2
VCC
LTC2917-B
VM
SEL1
RST
Open
SEL2
WDI
GND
TOL
GND
TOL
Tolerance
–5%
VCC
–10%
Open
–15%
GND
Some applications require a valid reset signal down to low supply voltages in order
to prevent low voltage components from generating erroneous data or malfunction
as a system powers up or down. Linear Technology supervisors guarantee a valid
reset signal to an industry leading low of 0.5V to help preserve system integrity.
4
3
2
Allowable Glitch Duration vs Magnitude
1
0
1
2
3
4
SUPPLY VOLTAGE, VCC (V)
Glitch Immunity
5
DC supplies can have high frequency variation from sources such as load
transients, noise and pickup, all of which can cause spurious outputs at RST.
Linear Technology supervisors combat glitches using voltage-dependent
response time filtering, providing rejection of small, short duration glitches
and faster response times as monitor overdrive increases.
MAXIMUM ALLOWABLE GLITCH DURATION (µs)
RST VOLTAGE (V)
VCC
Guaranteed RESET for Supply Voltages ≥ 0.5V
10k PULL-UP R TO VCC
SEL1 = SEL2 = TOL = 0V
5 VM = 0.5V
0
SEL1
12V
System Voltage Tolerance Settings
RST Output Voltage vs VCC
6
Nominal Voltage
300
250
200
RESET OCCURS
ABOVE CURVE
150
100
50
0
L, LT, LTC, LTM, Linear Technology and the Linear logo are
registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
1
10
100
0.1
GLITCH PERCENTAGE PAST THRESHOLD (%)
WT
RT
LTC®2910 8 (8)
LTC2933 6 (6)
Adj
Adj
1.5
1
Adj
Adj
50
700
•
•
•
LTC2936
6 (6)
Adj
1
Adj
700
•
•
LTC2939
LTC2908
6 (4)
6 (5)
1.5
1.5
Adj
200ms
80
26
LTC2930
LTC2931
LTC2932
LTC2900
LTC2938
LTC2901
6 (4)
6 (4)
6 (4)
4 (2)
4 (2)
4 (2)
5 to 1.2
5, 3.3, 2.5, 1.8,
1.5
5 to 1.5
5 to 1.5
5 to 1.5
5 to 1.5
5 to 1.2
5 to 1.5
1.5
1.5
1.5
1.5
1.5
1.5
Adj
Adj
Adj
Adj
Adj
Adj
52
52
52
43
80
43
LTC2902
4 (2)
5 to 1.5
1.5
Adj
43
LTC2903
4 (3)
1.5
200ms
20
LTC2914
LTC2911
4 (4)
3 (2)
1.5
1.5
Adj
70
30
LTC1326
LTC1536
LTC1726
LTC1727
LTC1728
LTC2919
3 (1)
3 (1)
3 (1)
3 (1)
3 (1)
3 (2)
5, 3.3, 2.5,
1.8, –5.2
Adj
5, 3.3, 2.5,
1.8, 1.2
5, 3.3, 2.5
5, 3.3
5, 3.3, 2.5
5, 3.3, 3, 2.5
5, 3.3, 3, 2.5, 1.8
5, 3.3, 2.5
0.75
0.75
1.5
1.5
1.5
1.5
200ms
200ms
Adj
200ms
200ms
Adj
40
200
20
15
15
50
LTC2909
3 (2)
5, 3.3, 2.5
1.5
Adj
50
LTC2966
2 (2)
Adj
1.4
LTC2960
2(2)
Adj
1.5
LTC2913
2 (2)
Adj
1.5
LTC1696
LTC2904
LTC2905
LTC2906
LTC2907
LTC2934
2 (2)
2 (0)
2 (0)
2 (1)
2 (1)
2 (2)
Adj
5 to 1
5 to 1
5, 3.3, 2.5
5, 3.3, 2.5
Adj
2
1.5
1.5
1.5
1.5
1.5
LTC2965
1 (1)
Adj
1.4
LTC2935
LTC2915
LTC2916
LTC2917
LTC2918
LTC2912
LTC1232
1 (1)
1 (1)
1 (1)
1 (1)
1 (1)
1 (1)
1 (0)
1.6 to 3.5
12 to 0.5
12 to 0.5
12 to 0.5
12 to 0.5
Adj
5
1.5
1.5
1.5
1.5
1.5
1.5
2.5
LTC1235
LTC690
LTC691
LTC694
LTC695
1 (0)
1 (0)
1 (0)
1 (0)
1 (0)
5
5
5
5, 3.3
5, 3.3
2
2
2
2
2
Adj
200ms
Adj
200ms
Adj
15ms/
200ms
200ms
Adj
Adj
Adj
Adj
Adj
600ms
200ms
50ms
50ms
200ms
200ms
•
•
•
•
Adj
•
•
•
•
•
44
•
1.1mA
65
65
50
54
0.5
•
•
•
•
6
600
600
600
600
600
•
•
•
•
•
•
•
•
Adj
Adj
•
C, I, H
3 × 3 DFN-12
C, I, H
TSSOP-20
C, I, H
TSSOP-20
C, I MSOP-10, 3 × 3 DFN-10
C, I, H
MSOP-16
C, I
SSOP-16
• UV/OV Outputs, Optional Shunt Reg For High Voltage Operation
Margining Latch, Guaranteed Reset for VCC ≥ 0.5V
Separate Voltage Monitor Outputs
0.85
0.5
30
30
30
30
40
500
16 Pin-Selectable Reset Thresholds Combinations
16 Pin-Selectable Reset Thresholds Combinations, Separate Voltage Monitor Outputs
16 Pin-Selectable Reset Thresholds Combinations, Separate Voltage Monitor Outputs
16 Pin-Selectable Reset Threshold Combinations, Open Drain or Push-Pull Reset Output
16 Pin-Selectable Reset Thresholds
16 Pin-Selectable Reset Thresholds, Separate Voltage Monitor Outputs,
Open Drain or Push-Pull Reset Output
• 16 Pin-Selectable Reset Thresholds, Separate Voltage Monitor Outputs,
Open Drain or Push-Pull Reset Output
Guaranteed Reset for VCC ≥ 0.5V
Reset and Soft Reset Outputs
Reset and Soft Reset Outputs, Added Tests for PCI Conformity
•
•
•
•
•
•
•
•
•
•
Package
• Resistor Programmable Thresholds, RST & RST Outputs, Shunt Regulator
C, I, H SSOP-16, 5 × 3 DFN-16
• I2C Programmable, EEPROM, 256 Thresholds, One High Voltage Input, Two GPIs, C, I
SSOP-16, 5 × 4 DFN-16
Three GPIOs, Two Auxilliary Comparators with Resistor Adjustable Thresholds
• I2C Programmable, EEPROM, 256 Thresholds, Six Comparator Outputs, Two GPI, C, I
SSOP-24, 4 × 5 QFN-24
Three GPIO, Two Auxilliary Comparators with Resistor Adjustable Thresholds
• 16 Pin-Selectable Reset Threshold Combinations, Adj Reset and Watchdog Timers
C, I, H
MSOP-16
C, I
TSOT-8, 3 × 2 DFN-8
Guaranteed Reset for VCC ≥ 0.5V
•
•
•
•
•
•
•
Adj
Adj
12
15ms/
200ms
•
Adj
Comments
Temp Grades*
Watchdog Timer
Power Fail Warning
Manual Reset
OV Monitor
Negative Monitor
Reset
Pulse
Width
Supply Current (µA)
Accuracy (%)
# of Voltage Monitors
(# of Adj Inputs)
Part #
Monitor
Voltages
(V)
• Pin-Selectable Polarity for Negative and UV/OV Monitoring, Shunt Regulator,
VCC Separate Voltage Monitor Outputs, Guaranteed Reset for VCC ≥ 0.5V
• Pin-Selectable Polarity for Negative and UV/OV Monitoring, Shunt Regulator,
VCC Monitor, Guaranteed Reset for VCC ≥ 0.5V
• 3.5V to 100V Operation, Resistor Programmable Thresholds, Internal High Value
Resistive Dividers, Pin-Selectable Output Polarity
2.5V to 36V Operation, Resistor Programmable Thresholds
Resistor Programmable Reset Thresholds, UV/OV Outputs, Shunt Regulator,
Guaranteed Reset for VCC ≥ 0.5V
Resistor Programmable Reset Thresholds, Gate Drive for Crowbar
9 Pin-Selectable Reset Thresholds
9 Pin-Selectable Reset Thresholds
Pin-Selectable and Resistor Programmable Reset Thresholds
Pin-Selectable and Resistor Programmable Reset Thresholds
Resistor Programmable Reset Threshold
• 3.5V to 100V Operation, Resistor Programmable Thresholds, Internal High Value
Resistive Dividers, Pin-Selectable Output Polarity
8 Pin-Selectable Reset Thresholds
9 Pin-Selectable Reset Thresholds, 3 Tolerances
9 Pin-Selectable Reset Thresholds
9 Pin-Selectable Reset Thresholds, 3 Tolerances
9 Pin-Selectable Reset Thresholds
Resistor Programmable Reset Threshold, UV/OV Outputs, Shunt Regulator
Conditional Battery Backup, RAM Protect
Battery Backup, 4.65V Reset
Battery Backup, RAM Protect, 4.65V Reset
Battery Backup, 4.65V Reset
Battery Backup, RAM Protect, 4.65V Reset
C, I
SSOP-16
C, I
TSOT-6
C, I, H
C, I, H
SSOP-16, 5 × 3 DFN-16
3 × 2 DFN-8, TSOT-8
C, I
MSOP-8, SO-8
C, I
MSOP-8, SO-8
C, I, H
MSOP-8, SO-8
C, E, I
MSOP-8, SO-8
C, E, H
TSOT-5
C, I, H MSOP-10, 3 × 2 DFN-10
C, I
TSOT-8, 3 × 2 DFN-8
C, I, H
SO-10, 3 × 3 QFN-16
C, I, H
TSOT-8, 2 × 2 DFN-8
C, I, H MSOP-10, 3 × 3 DFN-10
C, E
C, I
C, I, H
C, I
C, I
C, I
TSOT-6
TSOT-8, 3 × 2 DFN-8
TSOT-8, 3 × 2 DFN-8
TSOT-8, 3 × 2 DFN-8
TSOT-8, 3 × 2 DFN-8
TSOT-8, 2 × 2 DFN-8
C, I, H
MSOP-16, 3 × 3 DFN-8
C, I
TSOT-8, 2 × 2 DFN-8
C, I, H
TSOT-8, 3 × 2 DFN-8
C, I, H
TSOT-8, 3 × 2 DFN-8
C, I, H MSOP-10, 3 × 2 DFN-10
C, I, H MSOP-10, 3 × 2 DFN-10
C, I, H
TSOT-8, 3 × 2 DFN-8
C, I
DIP-8, SO-8
C
C, I
C, I
C, I
C, I
DIP-16, SO-16
DIP-8, SO-8
DIP-16, SO-16
DIP-8, SO-8
DIP-16, SO-16
* C = 0°C to 70°C, E = –40°C to 85°C (Guaranteed by Design Only), I = –40°C to 85°C, H = –40°C to 125°C (100% Tested)
www.linear.com/supervisors n 1-800-4-LINEAR
1214D