February 2005
rev 1.4
ASM1815
Low Power, 3.3V/3.0V µP Reset Active LOW, Push-Pull Output
Applications
• • • • • • • Set-top boxes Cellular phones PDAs Energy management systems Embedded control systems Printers Single board computers
General Description
The ASM1815 is a voltage supervisory device with low-power, 3.3V/3.0V µP Reset, active LOW, Push-Pull output. Maximum supply current over temperature is a low 15µA (at 3.6V). The ASM1815 generates an active LOW reset signal whenever the monitored supply is out of tolerance. A precision reference and comparator circuit monitor power supply (VCC) level. Tolerance level options are 5%, 10% and 20%. When an out-oftolerance condition is detected, an internal power-fail signal is generated which forces an active LOW reset signal. After VCC returns to an in-tolerance condition, the reset signal remains active for 150ms to allow the power supply and system microprocessor to stabilize. The ASM1815 is designed with a push-pull output stage and operates over the extended industrial temperature range. Devices are available in TO-92 and compact surface mount SOT-23 packages. Other low power products in this family include the ASM1810/ 11/12/16/17, ASM1233D and ASM1233M.
Typical Operating Circuit
VCC
ASM1815
Microprocessor
RESET RESET
GND
Key Features
• Low Supply Current •20 µA maximum (5.5 V) •15 µA maximum (3.6 V) • • • • • • • • Automatically restarts a microprocessor after power failure 150ms reset delay after VCC returns to an in-tolerance condition Active LOW power-up reset Precision temperature-compensated voltage reference and comparator Eliminates external components TO-92 and compact surface mount SOT-23 package Push-Pull output for minimum current drain Operating temperature -40°C to +85°C
Block Diagram
VCC 2
Supply Tolerance Bias
ASM1815
+
Reference
Delay 150ms Typical
1
RESET
3
GND
Alliance Semiconductor 2575 Augustine Drive . Santa Clara, CA 95054 . Tel: 408.855.4900 . Fax: 408.855.4999 . www.alsc.com
Notice: The information in this document is subject to change without notice
February 2005
rev 1.4
ASM1815
Pin Configuration
TO-92 SOT-23 RESET 1
ASM1815-R
ASM1815
3 GND
VCC
2 1 2 3
Pin Description
TO-92 Pin # 1 2 3 SOT-23 Pin Name Pin # 1 2 3 RESET VCC GND Active LOW reset output Power supply input Ground Description
Low Power, 3.3V/3.0V µP Reset
Notice: The information in this document is subject to change without notice
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ASM1815
VCC VCCTP (MAX) tF
Application Information
Operation - Power Monitor The ASM1815 detects out-of-tolerance power supply conditions. It resets a processor during power-up, powerdown and issues a reset to the system processor when the When an out-of-tolerance VCC voltage is detected, the RESET signal is asserted. On power-up, RESET is kept active (LOW) for approximatley 150ms after the power supply voltage has reached the selected tolerance. This allows the power supply and microprocessor to stablize before RESET is released.
tR VCCTP (MAX) VCCTP (MIN) VCCTP
VCCTP
VCCTP (MIN)
RESET
tRPD
VOL Figure 2: Timing Diagram: Power-Down
Output Conditions The ASM1815 active LOW reset signal is valid as long as VCC remains below 1.2V. The RESET output on the
ASM1815 uses a push-pull drive stage that can maintain a
VCC
tRPU
valid output below 1.2V. To sink current with VCC below 1.2V, a resistor can be connected from the reset pin (RESET) to Ground (see Figure 3). This configuration will give a valid value on the RESET output with VCC approaching 0V. During both power up and down, this configuration will draw current when the RESET is in the high state. A value of 100kΩ should be adequate to maintain a valid connection.
VOH
RESET
Figure 1: Timing Diagram: Power-Up
ASM1815
Microprocessor
RESET 100kΩ RESET
Figure 3: RESET Valid to 0V VCC
~ ~
3 of 9
monitored power supply voltage is below the reset threshold.
~ ~ ~ ~
Low Power, 3.3V/3.0V µP Reset
Notice: The information in this document is subject to change without notice
February 2005
rev 1.4
ASM1815
Absolute Maximum Ratings
Parameter Voltage on VCC Voltage on RESET Operating Temperature Range Soldering Temperature (for 10 sec) Storage Temperature -55 Min -0.5 -0.5 -40 Max 7 VCC + 0.5 85 260 125 Unit V V °C °C °C
ESD rating HBM MM 2 200 KV V
NOTE: These are stress ratings only and functional use is not implied. Exposure to absolute maximum ratings for prolonged periods of time may affect device reliability.
Electrical Characteristics
Unless otherwise noted, VCC= 1.2V to 5.5V and specifications are over the operating temperature range of -40°C to +85°C. All voltages are referenced to ground
Parameter Supply Voltage Output Voltage Output Current Output Current Operating Current Operating Current VCC Trip Point (ASM1815R-5) VCC Trip Point (ASM1815R-10) VCC Trip Point (ASM1815R-20) Output Capacitance VCC Detect to RESET Low VCC Slew Rate (VCCTP (MAX) to VCCTP (MIN) VCC Slew Rate (VCCTP (MIN) to VCCTP (MAX) VCC Detect to RESET High Symbol VCC VOH IOH IOL ICC ICC VCCTP VCCTP VCCTP COUT tRPD tF tR tRPU tr = 5µs 300 0 100 150 250 2 IOUT < 500 µA Output = 2.4V, VCC > 2.7V Output = 0.4V, VCC > 2.7V VCC < 5.5V, RESET output open VCC < 3.6V, RESET output open 2.98 2.80 2.47 +10 8 6 3.06 2.88 2.55 20 15 3.15 2.97 2.64 10 5 Conditions Min 1.2 VCC - 0.5V VCC - 0.1V 350 Typ Max 5.5 Unit V V µA mA µA µA V V V pF µs µs ns ms
Note: The tF value is for reference in defining values for tRPD and should not be considered for proper operation or use.
Low Power, 3.3V/3.0V µP Reset
Notice: The information in this document is subject to change without notice
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February 2005
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ASM1815
Package Dimension Plastic SOT-23 (3-Pin)
D B
E
H
S
e
A C L
a A1 e1
Inches
Millimeters
Min
Max
Min
Max
Plastic SOT-23 (3-Pin)
A A1 B C D E e e1 H L a S 0.030 0.002 0.012 0.003 0.110 0.047 0.046 0.006 0.020 0.008 0.120 0.055 0.75 0.05 0.30 0.08 2.80 1.20 0.95 BSC 1.9 BSC 2.10 0.40
0 o
1.17 0.15 0.50 0.20 3.04 1.40
0.037 BSC 0.075 BSC 0.083 0.016
0 o
0.104 0.024
8 o
2.64 0.60
8 o
NA
NA 5 of 9
Low Power, 3.3V/3.0V µP Reset
Notice: The information in this document is subject to change without notice
February 2005
rev 1.4 To-92 (3-Pin)
ASM1815
Dimensions in Inches Min Max TO-92 A b C φD E e e1 j L s 0.175 0.016 0.014 0.175 0.138 0.098 0.045 0.168 0.500 0.095 0.185 0.020 0.016 0.185 0.144 0.102 0.055 0.174 0.585 0.099
Dimensions in Millimeters Min Max
4.445 0.406 0.356 4.445 3.505 2.489 1.143 4.269 12.7 2.413
4.699 0.508 0.406 4.699 3.658 2.591 1.397 4.420 14.86 2.515
Low Power, 3.3V/3.0V µP Reset
Notice: The information in this document is subject to change without notice
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February 2005
rev 1.4
ASM1815
Family Selection Guide
Part # ASM1810 ASM1811 ASM1812 ASM1815 ASM1816 ASM1817 ASM1233D ASM1233M
RESET Voltage (V) 4.620, 4.370, 4.120 4.620, 4.350, 4.130 4.620, 4.350, 4.130 3.060, 2.880, 2.550 3.060, 2.880, 2.550 3.060, 2.880, 2.550 4.625, 4.375, 4.125 4.625, 4.375, 2.720
RESET Time (ms) 150 150 150 150 150 150 350 350
Output Stage Push-Pull Open-Drain Push-Pull Push-Pull Open-Drain Push-Pull Open-Drain Open-Drain
RESET Polarity LOW LOW HIGH LOW LOW HIGH LOW LOW
Low Power, 3.3V/3.0V µP Reset
Notice: The information in this document is subject to change without notice
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February 2005
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ASM1815
Ordering Information
Device Summary RESET Output Voltage (V) RESET Tolerance (%) RESET Time (ms) Push-Pull Output Stage SOT-23 Package RESET Polarity Package Marking
Part ** Number
TIN - LEAD DEVICES ASM1815R-5 ASM1815R-10 ASM1815R-20 LEAD FREE DEVICES ASM1815R-5F ASM1815R-10F ASM1815R-20F 3.06 2.88 2.55 RESET Output Voltage (V) 5 10 20 RESET Tolerance (%) 150 150 150 RESET Time (ms) Push-Pull Output Stage TO-92 Package LOW LOW LOW RESET Polarity KJLL KKLL KLLL Package Marking 3.06 2.88 2.55 5 10 20 150 150 150 LOW LOW LOW RJLL RKLL RLLL
Part ** Number
TIN - LEAD DEVICES ASM1815-5 ASM1815-10 ASM1815-20 LEAD FREE DEVICES ASM1815-5F ASM1815-10F ASM1815-20F 3.06 2.88 2.55 5 10 20 150 150 150 LOW LOW LOW ASM1815-5F ASM1815-10F ASM1815-20F 3.06 2.88 2.55 5 10 20 150 150 150 LOW LOW LOW ASM1815-5 ASM1815-10 ASM1815-20
* *Add /T to Part Number for Tape and Reel (i.e ASM18xx-x/T) LL- Lot Code
Low Power, 3.3V/3.0V µP Reset
Notice: The information in this document is subject to change without notice
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ASM1815
Alliance Semiconductor Corporation 2575, Augustine Drive, Santa Clara, CA 95054 Tel: 408 - 855 - 4900 Fax: 408 - 855 - 4999 www.alsc.com
Copyright © Alliance Semiconductor All Rights Reserved Part Number: ASM1815 Document Version: 1.4
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