Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - system monitor Dual voltage detector SOIC 16

1 of 15 060303

FEATURES

§ 2.5V power-on reset

§ 3.3V power-on reset

§ Two referenced comparators with separate

outputs for monitoring additional supplies

§ Internal power is drawn from higher of either

the IN

2.5V

input or the IN

3.3V

input

§ Excellent for systems designed to operate

with multiple power supplies

§ Asserts resets during power transients

§ Pushbutton reset input for system override

§ Maintains reset for user configurable times

of 10ms, 100ms, or 1s

§ Watchdog timer for software monitoring

(DS1831D)

§ Precision temperature-compensated voltage

reference and voltage sensor

§ 16-pin DIP and 16-pin 150mil SO available

§ Operating Temperature of -40°C to +85°C

PIN ASSIGNMENT

DESCRIPTION

The DS1831C multisupply monitor and reset monitors up to four system voltages: 2.5V supply, 3.3V (or

3V) supply, and two additional user configurable voltage monitors. DS1831 power for internal operation

comes from the higher voltage level of the 3.3V input or the 2.5V input. One of these inputs must be

greater than 1V for device operation. Pushbutton (manual reset) functionality is provided for the 2.5V

DS1831C/D/E

3.3V/2.5V Multisupply MicroMonitor

www.maxim-ic.com

3.3V

RST

3.3V

TOL

3.3V

PBRST

3.3V

MI1

MI2

MPBRST

2.5V

RST

2.5V

TOL

2.5V

PBRST

2.5V

IN1

IN2

GND

DS1831C

16-Pin (300mil) DIP

16-Pin

(

150mil

)

3.3V

RST

3.3V

TOL

3.3V

PBRST

3.3V

MI1

WDS

2.5V

RST

2.5V

TOL

2.5V

PBRST

2.5V

IN1

GND

DS1831D

16-Pin (300mil) DIP

16-Pin

(

150mil

)

3.3V

RST

3.3V

TOL

3.3V

PBST

MI1

MI2

MPBRST

2.5V

RST

2.5V

TOL

2.5V

PBRST

2.5V

IN1

IN2

GND

DS1831E

16-Pin (300mil) DIP

16-Pin

(

150mil

)

Summary of content (15 pages)

PAGE 1
DS1831C/D/E 3.3V/2.5V Multisupply MicroMonitor www.maxim-ic.com FEATURES § § § § § § § § § § § § 2.5V power-on reset 3.3V power-on reset Two referenced comparators with separate outputs for monitoring additional supplies Internal power is drawn from higher of either the IN2.5V input or the IN3.
PAGE 2
DS1831C/D/E reset, the 3.3V reset or for all reset outputs by the master pushbutton. The DS1831D replaces one reference comparator and the master pushbutton with watchdog and the DS1831E replaces the 3.3V PBRST with a last reset status output. TOL and TD inputs allow user configuration of the DS1831 for multiple applications. The TOL inputs configure the tolerance for the specified output and the TD inputs configure the reset time delays. PIN DESCRIPTION IN2.5V 2.5V Power Supply Input RST 2.5V 2.
PAGE 3
DS1831C/D/E BLOCK DIAGRAM Figure 1 IN2.5V 100 kW PBRST2.5V TD2.5V VCC TOL2.5V TOLERANCE BIAS 1.25V T.C. REFERENCE + TIME DELAY - 100 kW MPBRST RST2.5V Level Sense & Debounce IN3.3V 100 kW PBRST3.3V TD3.3V TOL3.
PAGE 4
DS1831C/D/E OPERATION—POWER MONITOR The DS1831 provides the functions of detecting out-of-tolerance conditions on a 3.3V (or 3V) and 2.5V power supply and warning a processor based system of impending power failure. When an input is detected as out-of-tolerance on either voltage input the RST for that supply will be forced active low.
PAGE 5
DS1831C/D/E PUSHBUTTON RESET SEQUENCING Figure 2 3.3V Supply 2.5V Supply IN2.5V RST2.5V TOL2.5V TD2.5V PBRST2.5V 16 1 2 15 DS1831C 14 3 4 13 5 12 IN3.3V RST3.3V TOL3.3V TD3.3V PBRST3.3V GND NOTE: The RST 2.5 volt output is connected to the IN3.3V via a 100kW resistor in the pushbutton input and therefore does not require a pull-up resistor (an addition pull up can be used to accelerate responses.) If an external pull-up is used in this example it must be connected to the 3.3V power supply.
PAGE 6
DS1831C/D/E PUSHBUTTON RESET Figure 3 2.5V Supply IN2.5V 10 kW RST2.5V 1 16 2 DS1831C 15 3 14 4 13 5 12 TOL2.5V TD2.5V PBRST2.5V GND TIMING DIAGRAM—MASTER PUSHBUTTON RESET Figure 4 tPB MPBRST tPDLY VIH VIL tRST RST2.5V and RST3.3V VOH NMI1 and NMI2 tNMI VOH TIMING DIAGRAM—2.5V OR 3.3V PUSHBUTTON RESET Figure 5 tPB PBRST2.5V (or PBRST3.3V) tPDLY VIH VIL tRST RST2.5V (or RST3.
PAGE 7
DS1831C/D/E OPERATION—PUSHBUTTON STATUS The DS1831E provides a master pushbutton status open drain output. The PBST output indicates the status of the most recent reset condition. If the last reset was generated by the master pushbutton input it would maintain a low condition until cleared by another event (except the master pushbutton) generating a reset. Once cleared it will remain high until the master pushbutton is pulled low generating a reset condition.
PAGE 8
DS1831C/D/E APPLICATION DIAGRAM—OPEN DRAIN OUTPUTS Figure 7 3.3V Supply 2.5V Supply IN2.5V 10 KW RST2.5V TOL2.5V TD2.5V PBRST2.5V 1 16 2 15 DS1831C 3 14 4 13 5 12 IN3.3v RST3.3V 10 KW TOL3.3V TD3.3V PBRST3.3V GND NOTE: If outputs are at different voltages the outputs can not be connected to form a wired AND.
PAGE 9
DS1831C/D/E TIMING DIAGRAM—NON-MASKABLE INTERRUPT Figure 8 VIN >1.25 V VTP(max) VTP VTP(min) VTP VTP(min) VTP(max) tNMI NMI tIPD VOH VOL NON-MASKABLE INTERRUPT CIRCUIT EXAMPLE Figure 9 VSENSE1 VSENSE2 VCC R1 PBRST3.3V PBRST2.5V R3 R2 IN1 DS1831C IN2 R4 NMI1 10 kW NMI2 GND MPBRST Example: VSENSE1 = 11.50 volts trip point Therefore: 11.50V = R1 + 100 kW 100 kW VSENSE1 = X 1.25V Resulting In: R1 = 820 kW Repeat the same steps to solve for R3 and R4 with VSENSE2.
PAGE 10
DS1831C/D/E OPERATION—WATCHDOG TIMER The watchdog timer function (DS1831D only) forces the WDS signal active (low) when the ST input does not have a transition (high-to-low or low-to-high) within the predetermined time period. The time-out period is determined by the condition of the TDWD pin (see Table 1). If TDWD is connected to ground the minimum watchdog time-out would be 10ms, TD floating would yield a minimum time-out of 100ms, and TDWD connected to VCC would provide a time-out of 1000ms minimum.
PAGE 11
DS1831C/D/E TIMING DIAGRAM—STROBE INPUT Figure 11 INVALID EDGES VALID EDGES INDETERMINATE EDGES ST MIN tST MAX tTD WDS RESET TIMING DIAGRAM—POWER UP Figure 12 tR VINTP (MAX) VINTP (MIN) VINTP IN2.5V (or IN3.3V) tRPU VOH RST2.5V (or RST3.
PAGE 12
DS1831C/D/E RESET TIMING DIAGRAM—POWER DOWN Figure 13 IN2.5V (or IN3.3V) VINTP (MAX) RST2.5V (or RST3.
PAGE 13
DS1831C/D/E ABSOLUTE MAXIMUM RATINGS* Voltage on IN2.5V or IN3.3V Pins Relative to Ground Voltage on either RST Relative to Ground Voltage on PBRST3.3V Relative to Ground Voltage on PBRST2.5V Relative to Ground Voltage on MPBRST, IN1, IN2 Relative to Ground Operating Temperature Range Storage Temperature Range Soldering Temperature * -0.5V to +6.0V -0.5V to the greater of IN2.5V + 0.5V or IN3.3V + 0.5V -0.5V to IN3.3V + 0.5V -0.5V to IN2.5V + 0.5V -0.5V to the greater of IN2.5V + 0.5V or IN3.3V + 0.
PAGE 14
DS1831C/D/E CAPACITANCE PARAMETER Input Capacitance Input Capacitance (tA = +25°C) SYMBOL CIN COUT MAX 5 7 UNITS pF pF NOTES AC ELECTRICAL CHARACTERISTICS (-40° to 85°C; IN2.5V, IN3.3V = 1.0V to 5.
PAGE 15
DS1831C/D/E ORDERING INFORMATION Ordering Part Package Type Description Number DS1831C 16-Pin DIP 300mil 2.5V/3.3V Multisupply Monitor DS1831CS 16-Pin SO 150mil 2.5V/3.3V Multisupply Monitor DS1831D 16-Pin DIP 300mil 2.5V/3.3V Multisupply Monitor w/Watchdog DS1831DS 16-Pin SO 150mil 2.5V/3.3V Multisupply Monitor w/Watchdog DS1831E 16-Pin DIP 300mil 2.5V/3.3V Multisupply Monitor w/Pushbutton Status DS1831ES 16-Pin SO 150mil 2.5V/3.