AS1923A-BSTT-I

austriamicrosystems AG is now ams AG The technical content of this austriamicrosystems datasheet is still valid. Contact information: Headquarters: ams AG Tobelbaderstrasse 30 8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 e-Mail: ams_sales@ams.com Please visit our website at www.ams.com Datasheet AS1923 Q u a d - Vo l ta g e M i c r o p r o c e s s o r S u p e r v i s o r y C i r c u i t 1 General Description 2 Key Features „Simultaneous Quad-Voltage Monitoring The AS1923 microprocessor supervisory circuit was designed to monitor up to four system supply voltages without the need for external components, and asserts a single reset if any of the monitored supply voltages drops below its reset threshold. +3.3, +3.0, +2.5, +1.8, and -5.0V „Low Supply Current: 55μA „Open-Drain – AS1923A „Reset Timeout Period: 120ms Minimal external component requirements, small size, and wide temperature range (-40 to +85°C) greatly improves reliability compared to individual supervisory circuits or discrete components. lv „10μA Current Source Pullup – AS1923B al „User-Adjustable Voltage Monitoring Threshold Options The AS1923 features an active-low reset output that is asserted when any of the 4 monitored voltages are below their respective reset threshold. The reset output is open-drain with a weak internal pullup (10μA) to IN2. Reset remains low for a specified reset timeout period (120ms min) after all voltages have stabilized. The output is valid as long as the IN1 or IN2 input voltage remains >1V. id „Precision Factory-Trimmed Reset Threshold Options: +5.0, ni ca a l c ms on A te G nt st il „RESET ES Valid to IN1 = 1V or IN2 = 1V „Immune to Fast INx Transients ents „External ternal Com Components C not Required A wide range of factory-trimmed threshold voltages are available to accommodate many different supply voltages/tolerances with minimal external component requirements. „Guarant Guaranteed Performance: orm e: Operating Temperature Range = -40 +85ºC to ++8 Factory-trimmed options are available for monitoring +5.0, +3.3, +3.0, +2.5, +1.8, and -5.0V supplies with -5% and/or -10% tolerer erances. The device is also available with one or two user-adjustable djustable ustable threshold options (via external resistor-divider network)) if non-standard voltage thresholds are required. „6-pin SOT23 T23 Package The AS1923 is available in an 6-pin SOT23 package. ckage. kage 3 App Applications The ddevice is ideal for portable and battery-powered systems, eembedded controllers, intelligent instruments, automotive systems, em critical CPU monitoring, and any multi-supply application. Figure 1. AS1923 - Typical Application Monitoring oring Voltage oltage e1 Monitoring Voltage 2 Te ch Monitoring Monitor Vo Volta Voltage 3 Monitoring Voltage 4 4 IN1 N1 5 IN2 AS1923 6 3 RESETN RESETN CPU IN3 1 IN4 www.austriamicrosystems.com/Supervisors/AS1923 GND 2 Revision 1.01 1 - 16 AS1923 Datasheet - P i n o u t 4 Pinout Pin Assignments Figure 2. Pin Assignments (Top View) Pin Descriptions Table 1. Pin Descriptions Pin Number Pin Name 1 IN4 2 GND RESETN 4 IN1 5 IN2 6 IN3 4 IN1 Description D Input Voltage 4. See Orderingg Info Information ation ion on page 14 for monitored volta voltages. Ground Reset Output. AS1923A 923A 23A (see Orde Ordering Information mation ation on page 14) 14 supports an external pullup resistor; AS1923B contains an internal rnal nal 10μA current curren curre source pullup. p. RESETN goes go low (reset asserted) when any one of the INx voltages goess below its specified threshold. spec spe shold. d. After all inputs input inpu have stabilized, RESETN remains low for at least 120ms (min) min) in) before going goi high. Input Voltage page ltage tage 11.. See Orderingg Information ormation on pa pag 14 for monitored voltages. Input Voltagee 22. See Ordering dering ng Information oon page 14 for monitored voltages. Note: IN2 is the powerr supply upply input inpu for the AS1923. Input Voltage 3.. See O Ordering Information on page 14 for monitored voltages. ng Infor Te ch ni 3 5 IN2 ca a l c ms on A te G nt st il RESETN 3 AS1923 al id GND 2 6 IN3 lv IN4 1 www.austriamicrosystems.com/Supervisors/AS1923 Revision 1.01 2 - 16 AS1923 Datasheet - A b s o l u t e M a x i m u m R a t i n g s 5 Absolute Maximum Ratings Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in Electrical Characteristics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 2. Absolute Maximum Ratings Min Max Units IN1, IN2 (Monitored Voltage), IN3, IN4 to GND -0.3 +7 V IN4 to GND (Device Variants M, N, O, and P, see Table 5 on page 14) -7 +0.3 V RESETN to GND -0.3 +6 V Latchup immunity Comments va lid Parameter Electrical Parameters Class I Level A in accordance with wit EIA/JEDEC /JEDEC 78 Continuous Power Dissipation am lc s on A te G nt st ill Continuous Power Dissipation (TAMB = +70ºC) 696 mW W Derate 8.7mW/ºC mW/ºC W/ºC above +70ºC Temperature Ranges and Storage Conditions Junction Temperature Storage Temperature Range -55 Package Body Temperature Humidity non-condensing ºC ºC +260 60 ºC 855 % 1 The reflow peak pea soldering temperature (body temperature) specified is in accordance with IPC/JEDEC mperature) rature) specifie J-STD-020 “Moisture/Reflow Sensitivity Classification for TD-020 “Moistu “Moistur Non-Hermetic on-Hermetic Solid State Surface Mount Devices”. The lead fin finish for Pb-free leaded packages is matte tin finis (100% Sn). Represents a max. floor life time of unlimited Te ch ni ca Moisture Sensitive Level 5 +150 150 +150 www.austriamicrosystems.com/Supervisors/AS1923 Revision 1.01 3 - 16 AS1923 Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s 6 Electrical Characteristics VIN2 = +1V to +5.5V, Typ values @ VIN2 = +3.0V to +3.3V, TAMB = +25ºC (unless otherwise specified). Table 3. Electrical Characteristics 1 Symbol Parameter Tamb Operating Temperature Range 2, 3 Min Typ Max Units -40 85 °C 1.0 5.5 V ch ni ca a l c ms on A te G nt st ill va lid VIN2 Conditions IINx Supply Voltage Range Input Current VINx = Input Threshold Voltage (Input Threshold Voltage of 1.8, 2.5, or 5V) 25 40 VIN2 = Input Threshold Voltage (Input Threshold 4 Voltage of 3.0 or 3.3V) 55 115 VINx = 0 to VIN2 5 (Input Threshold Voltage = +1.23V) μA μ -0.1 VIN1 = 1.5V (AS1923 K/L only) 0.4 hreshold V Voltage = -5V) VINx = -5V (Input Threshold VTH VTH Reset Threshold Voltage Adjustable Threshold -15 -20 4.50 4.63 4.63 4.75 creasing, reasing, +5V (-10%) Thresholdd VINx Decreasing, 4.25 4.38 4.50 reasing, +3.3V (-5%) ( Threshold reshold hold VINx Decreasing, 3.00 3.00 00 3.08 3.15 creasing, sing, +3.3V +3. (-10%) %) Threshold hreshold VINx Decreasing, 2.85 2.93 3.00 INxx Dec Decreasing, De sing +3.0V (-5%) Threshold VIN 2.70 2.78 2.85 INxx Decrea Decreasing, +3.0V Decr .0V (-10%) 10%) Threshold Thresho Threshol VIN 2.55 2.63 2.70 INxx D Decreasing, De g, +2.5V 2.5V (-10%) Threshold Thr Thre VIN 2.13 2.19 2.25 asing, g, +1.8V (-10%) (-10% Threshold VIINx Decreasing, 1.53 1.58 1.62 sing, -5V (+5% (+5 (+5%) Threshold VINx Increasing, -4.75 -4.63 -4.50 ncreasing, -5V (+10%) Threshold VINxx Increasing, -4.50 -4.38 -4.25 VIN INx Decreasing 1.20 1.23 1.26 Threshold Hysteresis Reset Delay ay tRP Reset Activee Timeout meout Period VINx = VTH to (VTH - 50mV), All Inputs Except -5V, or VINx = VTH to (VTH + 50mV), -5V Input Only 120 V V 60 ppm/ºC 0.5 % 20 μs 200 280 ms Te tRD 1.5 1.5 sing, g, +5V (-5%) Threshold Th T VINx Decreasing, Threshold Voltage Temperature Coefficient VHYS 0.11 www.austriamicrosystems.com/Supervisors/AS1923 Revision 1.01 4 - 16 AS1923 Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s Table 3. Electrical Characteristics (Continued) Symbol VOL Parameter 1 Output Low Voltage Conditions Min Typ Max VIN2 = 5V, ISINK = 2mA 0.4 VIN2 = 2.5V, ISINK = 1.2mA 0.4 VIN1 = VIN2 = 1V, ISINK = 50μA IOH 0.4 6 Output High Voltage, Output High Source Current VIN2 > 2.55V, ISOURCE = 6μA (Reset Not Asserted) 0.8 x VIN2 5 Output High Source Current VIN2 t 2.55V (Reset Not Asserted), VOUT t 0.8 x VIN2 6 V 10 μA A 100% production tested at TAMB = +25ºC. Limits over temperature guaranteed by design. The device is powered from input IN2. The RESETN output is guaranteed to be in the correct state for IN1 or IN2 down to 1V. Monitored voltage at IN2 (+3.3V, +3.0V) is also the device power supply. Supply current split is 25μA for the resistor-divider or-dividerr network or-divide net n k (for (fo the monitored voltage) and 30μA for other circuits. 5. Adjustable pin only. 6. AS1923B only. am lc s on A te G nt st il lv 1. 2. 3. 4. V al id VOH Units Te ch ni ca Note: All limits are guaranteed. The parameters with min and max values are guaranteed g d with production productio tests or SQC (Statistical Quality Control) methods. www.austriamicrosystems.com/Supervisors/AS1923 Revision 1.01 5 - 16 AS1923 Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s 7 Typical Operating Characteristics Tamb = +25ºC, unless otherwise noted Figure 3. IN2 Input Current vs. IN2 Input Voltage Figure 4. IN2 Input Current vs. Temperature 70 75 70 65 60 55 3 65 3.5 VIN2 = 3.3V 60 4 4.5 5 VIN2 = 3.0V 55 50 -40 5.5 -20 IN2 Input Voltage (V) 0 20 40 60 8 80 Temperature(°C) ture(°C) Figure 5. Reset Delay vs. Reset Threshold Overdrive; VIN2 = 3.0V, IN decreasingVIN2 = 3.0V, IN decreasing 80 id IN2 Input Current (mA) . 80 ni ca a l c ms on A te G nt st ill va l IN2 Input Current (mA) . 85 Figure 6. Reset Timeout Periode Pe de vs. Temperature; Tempe Tempera Resett Timeout Periode Pe (ms) Reset Delay (μs) . . 225 60 40 20 0 0 200 400 600 00 800 1000 220 215 210 205 20 200 195 -40 Reset Threshold Overdrive e (mV) -15 10 35 60 85 Te ch Temperature (°C) www.austriamicrosystems.com/Supervisors/AS1923 Revision 1.01 6 - 16 AS1923 Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s Figure 7. Normalized Threshold Error vs. Temperature; VIN2 = 3.0V Normalized Threshold Error (%) . 0.1 VTH = 5.0V 0 VTH = 1.8V id -0.1 al -0.2 -0.4 -40 -20 0 20 40 60 lv -0.3 80 ca l c ms on A te G nt st il Temperature(°C) 2V/Div VIN1 VOUT 50ms/Div Te ch ni 5μs/Div 1V/Div 2V/Div Figure igure ure 9. Reset Act A Active Timeout ut Periode; riode; VIN22 = 3. 3.0 3.0V 1V/Div V/Di V/Div V/ VOUT VIN1 Figure 8. Reset Delay; VIN2 = 3.0V www.austriamicrosystems.com/Supervisors/AS1923 Revision 1.01 7 - 16 AS1923 Datasheet - D e t a i l e d D e s c r i p t i o n 8 Detailed Description The AS1923 is a very small, low-power, quad-voltage microprocessor supervisory circuit designed to maintain system integrity in multi-supply systems (see Figure 10). The device offers several factory-trimmed under-voltage threshold values that minimize or eliminate the need for external components. id Preset voltage monitoring values of +5.0, +3.3, +3.0, +2.5, +1.8, and -5.0V (see Ordering Information on page 14) are available for a wide range of applications such as telecommunications equipment, desktop and notebook computers, high-end printers, data storage equipment, and networking equipment applications. va l The device is powered via the IN2 input (3.0 to 3.3V) and a reset is asserted if VIN1 or VIN2 is > 1V. For improved performance, the AS1923 was also designed to ignore fast INx transients. Figure 10. AS1923 - Block Diagram 4 + Te ch ni ca a l c ms on A te G nt st ill IN1 – IN1 5 5V Pullup + IN2 3V V 3 – RESETN Timeout (220ms) 6 + IN3 – 1 + IN4 – Bandgap dga Reference rence AS1923 Optional on AS1923B Only The quad-voltage monitor/reset circuitry includes an accurate bandgap reference, four precision comparators, and a series of internal trimmed ad-voltage ge monitor/re monito resistor-divider stor-divider networks to set the factory-trimmed reset threshold values. networks scale the specified INx reset voltages to match the internal bandgap reference/comparator voltage. User-adjustable The resistor network netwo options bypass the internal resistor networks and connect directly to one of the comparator inputs (an external resistor-divider network threshold option is required quired for fo threshold matching). Eachh of the internal comparators has a typical hysteresis of 0.5% with respect to its reset threshold. This built-in hysteresis improves device immunity to ambient noise without significantly reducing threshold accuracy when an input sits at its specified reset voltage. Note: Threshold voltage options (fixed and adjustable) are designated by the single-letter code in the model number (see Ordering Information on page 14). www.austriamicrosystems.com/Supervisors/AS1923 Revision 1.01 8 - 16 AS1923 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 9 Application Information Reset Output Figure 11. RESETN Output Timing Diagram INx VTHL RESETN tRD tRP ch ni ca a l c ms on A te G nt st ill v 90% al id The AS1923 RESETN output is asserted low when any of the monitored INx voltages drop below its specified reset threshold (above for -5V option) and remains asserted for the duration of the reset timeout period (120ms minimum) after all inputs have stabilized (Figure 11). 10% The AS1923B output driver is driven by an internal 10μA current source pullup upp resistor. For FFo most applications ons there here is no need nee for an external pullup resistor to interface with other logic supplies. Note: An external pullup resistor must not be connected to the AS1923B. S1923B. The AS1923A supports an external pullup resistor to any voltage from non-standard logic supply voltages (see Figure om 0 to +5.5V iif interfaced ed too non-standa 12). Figure 12. Interfacing to Various Logic Supply Voltages es +5V V VCC 100k: : 3 RESETN SETN RESETN CPU AS1923A S1923A 2 Te GND www.austriamicrosystems.com/Supervisors/AS1923 Revision 1.01 9 - 16 AS1923 Datasheet - A p p l i c a t i o n I n f o r m a t i o n User-Adjustable Thresholds The AS1923 provides several voltage monitoring values as well as user-adjustable reset thresholds. The threshold voltage at each adjustable INx input is typically 1.23V. To monitor a voltage >1.23V, connect a resistor-divider network to the circuit as shown in Figure 13. R1 + R2 – + VREF = 1.23V am lc s on A te G nt st il – lv VINTH al id Figure 13. Setting User-Adjustable Thresholds For the circuit shown in Figure 13, calculate R1 and R2 as: or, calculated in terms of R1: R1 + R2 ---------23V u -----------------V INTH = 1,23V R2 (EQ 1) V INTH NTH H R 1 = R 2 u § ---------------------------- – 1· ©1 ¹ 1,23V 23V 3V V (EQ 2) Note: Because the AS1923 has a guaranteed aranteed anteed input inpu current of ±0.1μA 0.1μA on its adj aadjustable inputs, resistor values up to 100k: can be used for R2 with