AS1370 AMSCO
Document overview
- Manufacturer or author: Provided By digicamel.com
- PDF pages: 28
Technical content
[v2-00] 2016-Jun-01 Document Feedback AS1370 High Voltage, Low Quiescent Current, 200mA LDO The AS1370 low-power, positive voltage regulator is designed to deliver up to 200mA, while consuming only 3μA of quiescent current. The device is available in fixed output voltages between 1.2V and 5.5V (programmable in 100mV steps). also available. The input voltage ranges from 2.6V to a maximum of 50V. Operation wi th large input to output differential voltages is limited by the maximum power dissipation available from package and environment. The very-low dropout voltage (550mV @ 200mA load) prolongs battery life and allows high current in small applications with minimum input-to-output voltage differentials. The device features very stable output voltage (using only 1μF ceramic capacitor), and excellent line- and load-regulation. The AS1370 also features a Power-OK Output. The device features integrated short-circuit and over current protection. Thermal Protection shuts down the device when die temperature reaches 170°C. This is a useful protection when the device is under sustained short circuit conditions. The AS1370 is available in an 8-Pin MLPD 3mm x 3mm package and is qualified for -40°C to 125°C operation. Ordering Information and Content Guide appear at end of datasheet. Key Benefits & Features The benefits and features of AS1370, High Voltage, Low Quiescent Current, 200mA LDO are listed below: Figure 1: Added Value of Using AS1370 Benefits Features
- Ideal for industrial or automotive applications • Input voltage from 2.6V to 50V
- Operating temperature from -40°C to 125°C
- Ideal for a battery-driven always-on regulator • Very low quiescent current of 3μA
- Supports a variety of end applications
- Guaranteed output current of 200mA
- Output voltage from 1.2V to 5.5V
- Power-OK indication General Description
Document Feedback [v2-00] 2016-Jun-01 AS1370 − General Description
Applications
The wide input voltage range, low quiescent current and high-accuracy output voltage make the devices perfectly suited for a wide variety of industrial sensors, automotive and battery-powered applications, where the regulators have to be always on. The devices are also ideal for many other industrial applications. Figure 2: AS1370 Typical Application Diagram
- Over-temperature and over-current protection and shutdown
- Integrated temperature and output power monitoring
- Cost-effective, small PCB area needed • Less external components needed
- Small 8-pin MLPD 3mm x 3mm package Benefits Features AS1370 IN SHDN OUT POK COUT 1uF CIN 1uF Output 1.2V to 5.5V GND ON OFF Input 2.6V to 50V
[v2-00] 2016-Jun-01 Document Feedback AS1370 − General Description Block Diagram The functional blocks of this device are shown below: Figure 3: AS1370 Block Diagram Thermal Overload Protection Trimmable Reference Voltage & Noise Bypass Bandgap Voltage Current Reference Power-OK Compare Logic Error Amplifier AS1370IN SHDN OUT GND POK Enable Block Shutdown/ Power-On Control Logic
[v2-00] 2016-Jun-01 Document Feedback AS1370 − Absolute Maximum Ratings Stresses beyond those listed in Absolute Maximum Ratings 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 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Figure 6: Absolute Maximum Ratings Parameter Min Max Units Notes Electrical Parameters IN -0.9 +55 V SHDN -0.3 VIN + 0.3 V OUT -0.3 VIN + 0.3 V POK -0.3 VOUT + 0.3 V Latch-Up Immunity -100 +100 mA Electrostatic Discharge Electrostatic Discharge HBM ±1.5 kV MIL 883 E method 3015 Temperature Ranges and Storage Conditions Thermal Resistance θJA 36 °C/W Junction-to-ambient thermal resistance is very dependent on application and board-layout. In situations where high maximum power dissipation exists, special attention must be paid to thermal dissipation during board design. Operating Temperature Range -40 125 °C Storage Temperature Range -65 150 °C Package Body Temperature 260 °C The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD-020 “Moisture/Reflow Sensitivity Classification for Non-Hermetic Solid State Surface Mount Devices” . The lead finish for Pb-free leaded packages is matte tin (100% Sn). Relative Humidity (non-condensing) 58 5 % Moisture Sensitivity Level 1 Represents a max. floor life time of “Unlimited” Absolute Maximum Ratings
Document Feedback [v2-00] 2016-Jun-01 AS1370 − Electrical Characteristics All limits are guaranteed. The parameters with Min and Max values are guaranteed with production tests or SQC (Statistical Quality Control) methods. VIN = V OUT(NOMINAL) + 1V, or V IN = 2.6V (whichever is greater), SHDN = GND, C IN = COUT = 1μF, I OUT = 100μA; TAMB = -40°C to 125°C (unless otherwise specified); typical values are at T AMB = 25ºC. Figure 7:
Electrical Characteristics
Symbol Parameter Conditions Min Typ Max Units VIN Input voltage 2.6 50 V VOUT Output voltage 1.2 5.5 V Acc DC output voltage accuracy TAMB = 25°C -1 +1 %TAMB = -40°C to 125°C, IOUT = 100μA to 200mA -4 +4 ILIM Short circuit current 230 370 mA IQ Ground pin current IOUT = 0mA 38 μAIOUT = 200mA 3.7 TAMB = 85°C, IOUT = 0mA 6.7 VDROP Dropout voltage(1) IOUT = 100mA 280 600 mVIOUT = 200mA 550 TAMB = 85°C, IOUT = 100mA 500 ∆VLNR Line regulation(2) VIN = VOUT(NOMINAL) + 1V to 50V -0.05 +0.05 %/V ∆VLDR Load regulation IOUT = 1mA to 200mA 0.01 %/mA PSRR Power Supply Rejection Ratio f = 1kHz, IOUT = 10mA 50 dB
[v2-00] 2016-Jun-01 Document Feedback AS1370 − Electrical Characteristics Note(s): 1. Dropout voltage = VIN - VOUT when VOUT is 100mV < VOUT for VIN = VOUT(NOMINAL) +1V (applies only to output voltages ≥ 2.6V). 2. VOUT(NOMINAL) ≥ 1.6V. 3. The rise and fall time of the shutdown signal must not exceed 100ns. 4. The delay time is defined as time required to set VOUT to 95% of its final nominal value. Shutdown(3) tON Exit delay from shutdown(4) 1.25 5 ms IOFF Shutdown current SHDN = VIN 0.6 1.2 μA VIH Shutdown digital input threshold SHDN decreasing 1.6 V VIL SHDN increasing 0.4 ISHDN Shutdown input bias current SHDN = VIN 0.1 30 nA Power-OK Output VPOK Power-OK voltage threshold VOUT falling 93 95 97 % VOUT Hysteresis 1 IPOK Power-OK leakage current 0 ≤ VPOK ≤ VOUT, VOUT in regulation 50 nA Thermal Protection TSHDN Thermal shutdown temperature 170 ºC ∆TSHDN Thermal shutdown hysteresis 15 ºC Symbol Parameter Conditions Min Typ Max Units
Document Feedback [v2-00] 2016-Jun-01 AS1370 − Detailed Description The AS1370 is a low-dropout, low-quiescent-current linear regulators intended for LDO regulator applications where output current load requirements range from no load to 200mA. The AS1370 also features a Power-OK output to indicate when the output is within 5% of final value, and also a Shutdown pin. Shutdown current for the whole regulator is typically 600nA. The device features integrated short-circuit and over current protection. Undervoltage lockou t prevents erratic operation when the input voltage is slowly decaying (e.g. in a battery powered application). Thermal protection shuts down the device when die temperature reaches 170°C. This is a useful protection when the device is under sustained short circuit conditions. Figure 3 shows the block diagram of the AS1370. It identifies the basics of a series linear regulator employing a P-Channel MOSFET as the control element. A stable 1.2V voltage reference (REF in Figure 3 ) is compared with an attenuated sample of the output voltage. Any difference between the two voltages (reference and sample) creates an output from the error amplifier that drives the series control element to reduce the difference to a minimum. The error amplifier incorporates additional buffering to drive the relatively large gate capacitance of the series pass P-channel MOSFET, when additional drive current is requi red under transient conditions. Input supply variations are absorbed by the series element, and output voltage variations with loading are absorbed by the low output impedance of the regulator. Output Voltages Standard products are factory-set with output voltages from 1.2V. A two-digit suffix of the part number identifies the nominal out (see Ordering Information ). Non-standard devices are available. For more information contact www.ams.com/contact. Power-OK Functionality The AS1370’s Power-OK is built around a N-channel MOSFET. The Power-OK feature is not active during shutdown and provides a power-on-reset function that can operate down to VIN = 1.2V. A capacitor to GND may be added to generate a power-on-reset delay. To obtain a logic-level output, connect a pull-up resistor from pin POK to pin OUT. Larger values for this resistor will help to minimize current consumption; a 100k Ω resistor is perfect for most applications (see Figure 2 ). Detailed Description
[v2-00] 2016-Jun-01 Document Feedback AS1370 − Detailed Description Current Limiting The AS1370 include current limiting circuitry to protect against short-circuit conditions. The circuitry monitors and controls the gate voltage of the P-channel MOSFET, limiting the output current to 370mA. The P-channel MOSFET output can be shorted to ground for an indefinite period of time without damaging the device. Thermal-Overload Protection The devices are protected against thermal runaway conditions by the integrated thermal sensor circuitry. Thermal shutdown is an effective tool to prevent die overheating since the power transistor is the principle heat source in the device. If the junction temperature exceeds 170°C, the thermal sensor starts the shutdown logic, at which point the P-channel MOSFET is switched off. After the device temperature has dropped by approximately 15°C, the thermal se nsor will turn the P-channel MOSFET on again. Note that this will be exhibited as a pulsed output under continuous th ermal-overload conditions. Note(s): The absolute maximum junction-temperature of 170°C should not be exceeding during continual operation.
[v2-00] 2016-Jun-01 Document Feedback AS1370 − Application Information Efficiency Low quiescent current and low input-output voltage differential are important in battery applications amongst others, as the regulator efficiency is directly related to quiescent current and dropout voltage. Efficiency is given by: Efficiency = % Where: I Q= Quiescent current of LDO measured. Power Dissipation The power dissipated by the internal series MOSFET PD(MAX) (Seriespass) is calculated as: PD(MAX) (Seriespass) = [W] Internal power dissipation PD(MAX) (Bias), result of the quiescent current required to bias the internal voltage reference and the error amplifier, is calculated as: PD(MAX) (Bias) = [W] The maximum power dissipation PD(MAX) (Total) of the LDO is calculated as: PD(MAX) (T otal) = PD (MAX) (Seriespass) + PD (MAX) (Bias) [W] (EQ2) VOUT ILOAD× (EQ3) VIN MAX() VOUT MIN()–() ILOAD MAX()× (EQ4) VIN MAX() IQ× (EQ5)
Document Feedback [v2-00] 2016-Jun-01 AS1370 − Application Information Junction Temperature Under operating conditions, the maximum junction temperature should not exceed 125°C. Regulating the maximum junction temperature requires knowledge of the heat path from junction to case Θ JC [°C/W] fixed by the IC manufacturer, and adjustment of the case to ambient heat path ΘCA [°C/W ] by manipulation of the PCB copper area adjacent to the IC position. Figure 17: Steady State Heat Flow Equivalent Circuit Total Thermal Path Resistance (junction-to-ambient) is determined by: θJA = θJC + θCS + θSA [ºC/W] Junction Temperature is determined by: TJ = PD (MAX) × θJA + TAMB [ºC] Junction TJ Package TC PCB TS Ambient TA RθJC RθCS RθSA RθJA (EQ6) (EQ7)
[v2-00] 2016-Jun-01 Document Feedback AS1370 − Application Information Explanation of Steady State Specifications Line Regulation Line regulation is defined as th e percentual change in output voltage when the input (or line) voltage is changed by a known quantity. It is a measure of the regulator’s ability to maintain a constant output voltage when the input voltage changes. More generally: Line Regulation = and is a pure number In practise, line regulation is referred to the regulator output voltage in terms of % / V OUT. This is particularly useful when the same regulator is available with numerous output voltage trim options. Line Regulation = [% / V] Load Regulation Load regulation is defined as the change of the output voltage when the load current is changed by a known quantity. It is a measure of the regulator’s ability to maintain a constant output voltage when the load changes. Load regulation is a measure of the DC closed loop output re sistance of the regulator. More generally: Load Regulation = [ Ω] In practise, load regulation is referred to the regulator output voltage in terms of % / mA. This is particularly useful when the same regulator is available with numerous output voltage trim options. Load Regulation = [% / mA] Setting Accuracy Accuracy of the final output voltage is determined by the reference accuracy and the input offset voltage of the error amplifier. When the regulator is supplied pre-trimmed, the output voltage accuracy is fully defined in the output voltage specification. The reference tolerance is given both at 25°C and over the full operating temperature range. (EQ8) ΔVOUT ΔVIN (EQ9) ΔVOUT ΔVIN VOUT (EQ10) ΔVOUT ΔIOUT (EQ11) ΔVOUT ΔIOUT VOUT
Document Feedback [v2-00] 2016-Jun-01 AS1370 − Application Information Total Accuracy Away from dropout, total steady state accuracy is the sum of setting accuracy, load regulation and line regulation. Generally: Total Accuracy % = Setting Accuracy % + Load Regulation % + Line Regulation % Explanation of Dynamic Specifications Power Supply Rejection Ratio (PSRR) Known also as Ripple Rejection, this specification measures the ability of the regulator to reject noise and ripple beyond DC. PSRR depends on a summation of the individual rejections of the error amplifier, reference and AC leakage through the series pass transistor. The specificatio n, in the form of a typical attenuation plot with respect to frequency, shows up the gain bandwidth compromises forced upon the designer in low load current conditions. Generally: PSSR = [dB] using lower case to indicate AC values Power supply rejection ratio is fixed by the internal design of the regulator. Additional filterin g must be provided externally. Output Capacitor ESR The series regulator is a negative feedback amplifier, and as such is conditionally stable. The ESR of the output capacitor is usually used to cancel one of the open loop poles of the error amplifier in order to produce a single pole response; maximum ESR should be less than 500m Ω. Excessive ESR values may actually cause instability by excessive changes to the closed loop unity gain frequency cro ssover point. The range of ESR values for stability is usually shown either by a plot of stable ESR versus load current, or a limit statement in the datasheet. Some ceramic capacitors exhi bit large capacitance and ESR variations in temperature. Z5U and Y5V capacitors may be required to ensure stability at temperatures below T AMB = -10°C. With X7R or X5R capacitors, a 1.0μF capacitor should be sufficient at all operating temperatures. Larger output capacitor values (>10μF) help to further reduce noise and improve load transi ent-response, stability and power-supply rejection. (EQ12) (EQ13) 20Log δVOUT δVIN
[v2-00] 2016-Jun-01 Document Feedback AS1370 − Application Information Input Capacitor An input capacitor at V IN is required for stability. It is recommended that a 1.0μF capacitor be connected between the AS1370 power supply input pin V IN and ground (capacitance value may be increased without limit subject to ESR limits). This capacitor must be located at a distance of not more than 1cm from the V IN pin and returned to a clean analog ground. Any good quality ceramic, tantalum, or film capacitor may be used at the input. Noise The regulator output is a DC voltage with superimposed noise on the output. The noise come s from three sources: the reference, the error amplifie r input stage and the output voltage setting resistors. Noise is a random fluctuation: if noise is not minimized in some applications, it will produce system problems. Load Transient Response The series regulator is a negative feedback system: therefore any change at the output will take a finite time to be corrected by the error loop. This “propagation time” is related to the bandwidth of the error loop. The initial response to an output transient comes from the output capacitance; during this time, ESR is the dominant mechanism causing voltage transients at the output. More generally: [V] Thus an initial +50mA change of output current will produce a -12mV transient when the ESR=240m Ω. Remember to keep the ESR within stability recommendations when reducing ESR by adding multiple parallel output capacitors. After the initial ESR transient, there follows a voltage drop during the time that the LDO fe edback loop takes to respond to the output change. This drift is approximately linear in time and sums with the ESR contribution to make a total transient variation at the output of: [V] Where: C LOAD = load capacitor [F]; T= propagation delay of the LDO [s]. (EQ14) δVTRANSIENT δIOUT ESR×= (EQ15) δVTRANSIENT δIOUT ESR T CLOAD ×=
Document Feedback [v2-00] 2016-Jun-01 AS1370 − Application Information This shows why it is convenient to increase the output capacitor value for a better support for fast load changes. Of course the formula holds for t < “propagation time” , so that a faster LDO needs a smaller cap at the load to achieve a similar transient response. For instance, 50mA load current step produces 50mV output drop if the LDO response is 1μs and the load cap is 1μF. There is also a steady state error caused by the finite output impedance of the regulator. Th is is derived from the load regulation specification discussed above. Turn On Time This specification defines the ti me taken for the LDO to awake from shutdown. The time is measured from the release of the shutdown pin to the time that the output voltage is within 5% of the final value. It assumes that the voltage at V IN is stable and within the regulator min and max limits. Shutdown reduces the quiescent current to very low, mostly leakage values (<1μA typ.). Thermal Protection To prevent operation under extreme fault conditions, such as a permanent short circuit at the output, thermal protection is built into the device. Die temperature is measured, and when a 170°C threshold is reached, the device enters shutdown. When the die cools sufficiently, the devi ce will restart (assuming input voltage exists and the device is enabled). Hysteresis of 15°C prevents low frequency oscillation between start-up and shutdown around the temperature threshold.
[v2-00] 2016-Jun-01 Document Feedback AS1370 − Package Drawings & Markings The device is available in a 8-Pin MLPD 3mm x 3mm package. Figure 18: Drawings and Dimensions Note(s): 1. Dimensions and tolerancing conform to ASME Y14.5M-1994 . 2. All dimensions are in millimeters. Angles are in degrees. 3. Coplanarity applies to the exposed heat slug as well as the terminal. 4. Radius on terminal is optional. 5. N is the total number of terminals. Package Drawings & Markings Symbol Min Nom Max A 0.70 0.75 0.80 A1 0 0.02 0.05 A3 0.20 REF L 0.30 0.40 0.50 b 0.23 0.30 0.38 D3 . 0 0 B S C E3 . 0 0 B S C D2 2.23 2.38 2.48 E2 1.49 1.64 1.74 e0 . 6 5 B S C aaa - 0.15 - bbb - 0.10 - ccc - 0.10 - ddd - 0.05 - eee - 0.08 - GreenRoHS
[v2-00] 2016-Jun-01 Document Feedback AS1370 − Ordering & Contact Information The device is available as the standard products listed in Figure 21 . Figure 21:
Ordering Information
Note(s): 1. Non-standard devices are available between 1.2V and 5.5V in 100mV steps. Buy our products or get free samples online at: www.ams.com/ICdirect Technical Support is available at: www.ams.com/Technical-Support Provide feedback about this document at: www.ams.com/Document-Feedback For further information and requests, e-mail us at: ams_sales@ams.com For sales offices, distributors and representatives, please visit: www.ams.com/contact Headquarters ams AG Tobelbaderstrasse 30
8141 Premstaetten
Austria, Europe Tel: +43 (0) 3136 500 0 Website: www.ams.com Ordering Code Output Voltage Package Marking Code Delivery Form Delivery Quantity AS1370-ATDT-27 2.7V 8-Pin MLPD 3mm x 3mm ASV1 Tape & Reel 1000 pcs/reel AS1370-ATDT-28 2.8V 8-Pin MLPD 3mm x 3mm ASV2 Tape & Reel 1000 pcs/reel AS1370-ATDT-33 3.3V 8-Pin MLPD 3mm x 3mm ASQA Tape & Reel 1000 pcs/reel AS1370-ATDT- SAMPLE(1) XX(1) 8-Pin MLPD 3mm x 3mm ASQK Tape & Reel 1000 pcs/reel Ordering & Contact Information
Document Feedback [v2-00] 2016-Jun-01 AS1370 − RoHS Compliant & ams Green Statement RoHS: The term RoHS compliant means that ams AG products fully comply with current RoHS directives. Our semiconductor products do not contain any chemicals for all 6 substance categories, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, RoHS compliant products are suitable for use in specif ied lead-free processes. ams Green (RoHS compliant and no Sb/Br): ams Green defines that in addition to RoHS compliance, our products are free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material). Important Information: The information provided in this statement represents ams AG knowledge and belief as of the date that it is provided. ams AG bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are unde rway to better integrate information from third parties. ams AG has taken and continues to take reasonable steps to prov ide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. ams AG and ams AG suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. RoHS Compliant & ams Green Statement
[v2-00] 2016-Jun-01 Document Feedback AS1370 − Copyrights & Disclaimer Copyright ams AG, Tobelbader Strasse 30, 8141 Premstaetten, Austria-Europe. Trademarks Registered. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used with out the prior written consent of the copyright owner. Devices sold by ams AG are covered by the warranty and patent indemnification provisions appe aring in its General Terms of Trade. ams AG makes no warranty, express, statutory, implied, or by description regarding th e information set forth herein. ams AG reserves the right to ch ange specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with ams AG for current information. This product is intended for use in commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications , such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by ams AG for each application. This product is provided by ams AG “AS IS” and any express or implied wa rranties, including, but not limited to the implied warranties of merchantability and fitness for a particular purpose are disclaimed. ams AG shall not be liable to recipient or any third party for any damages, including but not limite d to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of ams AG rendering of technical or other services. Copyrights & Disclaimer
Document Feedback [v2-00] 2016-Jun-01 AS1370 − Document Status Document Status Product Status Definition Product Preview Pre-Development Information in this datasheet is based on product ideas in the planning phase of development. All specifications are design goals without any warranty and are subject to change without notice Preliminary Datasheet Pre-Production Information in this datasheet is based on products in the design, validation or qualification phase of development. The performance and parameters shown in this document are preliminary without any warranty and are subject to change without notice Datasheet Production Information in this datasheet is based on products in ramp-up to full production or full production which conform to specifications in accordance with the terms of ams AG standard warranty as given in the General Terms of Trade Datasheet (discontinued) Discontinued Information in this datasheet is based on products which conform to specifications in accordance with the terms of ams AG standard warranty as given in the General Terms of Trade, but these products have been superseded and should not be used for new designs Document Status
[v2-00] 2016-Jun-01 Document Feedback AS1370 − Revision Information Note(s): 1. Page and figure numbers for the previous version may diff er from page and figure numbers in the current revision. 2. Correction of typographical er rors is not explicitly mentioned. Changes from1.11 (2014-Jan-04) to current revision 2-00 (2016-Jun-01) Page Content was updated to the latest ams design Added benefits to Key Features 1 Updated Package Drawings & Markings section 21 Revision Information
Document Feedback [v2-00] 2016-Jun-01 AS1370 − Content Guide
1 General Description
1 Key Benefits & Features
2 Applications
4P i n A s s i g n m e n t 5A b s o l u t e M a x i m u m R a t i n g s