TPS3818 Datasheet, PDF (1/16 Pages) Texas Instruments – Low Quiescent Current, Accurate Programmable-Delay Supervisory Circuit

TPS3818
www.ti.com ......................................................................................................................................................... SBVS106A – MAY 2008 – REVISED AUGUST 2008
Low Quiescent Current, Accurate Programmable-Delay
Supervisory Circuit
FEATURES
1
•23 Power-On Reset Generator with Adjustable
Delay Time: 1.25ms to 10s
• Very Low Quiescent Current: 2.4µA typ
• High Threshold Accuracy: 0.5% typ
• Fixed Threshold Voltages for Standard Voltage
Rails from 0.9V to 5V and Adjustable Voltage
Down to 0.4V Are Available
• Manual Reset (MR) Input
• Open-Drain RESET Output
• Temperature Range: –40°C to +125°C
• Small SOT23 and 2mm × 2mm QFN Packages
APPLICATIONS
• DSP or Microcontroller Applications
• Notebook/Desktop Computers
• PDAs/Hand-Held Products
• Portable/Battery-Powered Products
• FPGA/ASIC Applications
1.2V
3.3V
DESCRIPTION
The TPS3818xxx family of microprocessor
supervisory circuits monitor system voltages from
0.4V to 5.0V, asserting an open-drain RESET signal
when the SENSE voltage drops below a preset
threshold or when the manual reset (MR) pin drops to
a logic low. The RESET output remains low for the
user-adjustable delay time after the SENSE voltage
and manual reset (MR) return above the respective
thresholds.
The TPS3818 uses a precision reference to achieve
0.5% threshold accuracy for V_IT ≤ 3.3V. The reset
delay time can be set to 20ms by disconnecting the
C_T pin, 300ms by connecting the C_T pin to V_DD using
a resistor, or can be user-adjusted between 1.25ms
and 10s by connecting the C_T pin to an external
capacitor. When used with an external capacitor, the
TPS3818xxx gives a more accurate delay time than
the similar TPS3808xxx device. The TPS3818 has a
very low typical quiescent current of 2.4µA so it is
well-suited to battery-powered applications. It is
available in either a small SOT23 and an ultra-small
2mm × 2mm QFN PowerPAD™ package, and is fully
specified over a temperature range of –40°C to
+125°C (T_J).
DBV PACKAGE
SOT23
(TOP VIEW)
SENSE V_DD
TPS3818G12
RESET
C_{T GND}
SENSE V_DD
TPS3818G33
MR
RESET
C_{T GND}
V_I/O V_CORE
DSP
GPIO
GND
Typical Application Circuit
RESET
1
GND
2
MR
3
6
V_DD
5
SENSE
4
C_T
DRV PACKAGE
2mm x 2mm QFN
(TOP VIEW)
V_DD 1
6 RESET
SENSE
2
Power
PAD
5
GND
C_T 3
4 MR
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PowerPAD is a trademark of Texas Instruments.
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All other trademarks are the property of their respective owners.
3
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2008, Texas Instruments Incorporated