CS8391 CHERRY | Alldatasheet

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Technical content

Features

n 5V , 250mA Primary Output n 5V , 100mA Secondary Output n 3% Tolerance, Both Outputs n ON/OFF Control for Primary Output n Low Quiescent Current Drain (100µA VOUT2) n Low Reverse Current n Protection Features Reverse Battery (-15V) Short Circuit Overtemperature Package Options CS8391 5V/250mA, 5V/100mA Micropower Low Dropout Regulator with ENABLE CS8391

Description

*Note: Internally connected on 5 leaded package. Block Diagram Absolute Maximum Ratings Lead Temperature Soldering The CS8391 is a precision, dual 5V micropower linear voltage regula- tor. The switched primary output OUT1) supplies up to 250mA while the secondary (VOUT2) is capable of supplying 100mA. Both outputs have a maximum dropout voltage of 600mV and low reverse current. Quiescent current drain is typically 150µA when supplying 100µA from each output. The ENABLE input provides logic level control of the primary output. With the primary output disabled, quiescent current drain is typically 100µA when supplying 100µA from the secondary output. The CS8391 is extremely robust with protection provided for reverse battery, short circuit, and overtemperature on both outputs. The CS8391 is available in a 5-lead D 2PAK.

5 Lead D2PAK

Tab (Gnd) Consult factory for 8L and 16L SO, 8L and 16L PDIP, 7L D2PAK and 5L TO-220. 1. VIN 2. VOUT1 3. Gnd 4. VOUT2 5. ENABLE A Company ¨ Rev. 1/12/98 Cherry Semiconductor Corporation

2000 South County Trail, East Greenwich, RI 02818

Tel: (401)885-3600 Fax: (401)885-5786 Email: info@cherry-semi.com Web Site: www.cherry-semi.com

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT n Primary Output Stage (VOUT1) Output Voltage, VOUT1 100µA ² IOUT1 ² 250mA 4.85 5.00 5.15 V Dropout Voltage I OUT1 = 250mA 400 600 mV IOUT1 = 100µA 100 150 mV Line Regulation 6V ² V IN ² 26V 5 50 mV Load Regulation 1mA ² I OUT1 ² 250mA, VIN = 14V 5 50 mV Quiescent Current ENABLE = HIGH, VIN = 16V, 22 50 mA IOUT1 = 250mA Ripple Rejection f = 120Hz, I OUT1 = 125mA, 7V ² VIN ² 17V 60 70 dB Current Limit 260 400 mA Short Circuit Current Limit V OUT1 = 0V, VIN = 16V 25 mA Reverse Current V OUT1 = 5V, VIN = 0V 100 1500 µA n Secondary Output (VOUT2) Output Voltage, VOUT2 100µA ² IOUT2 ² 100mA 4.85 5.00 5.15 V Dropout Voltage I OUT2 = 100mA 400 600 mV IOUT2 = 100µA 100 150 mV Line Regulation 6V ² V IN ² 26V 5 50 mV Load Regulation 100µA ² I OUT2 ² 100mA, VIN = 14V 5 50 mV Quiescent Current ENABLE = LOW, VIN = 12.8V 100 150 µA ENABLE = HIGH, VIN = 16V, 8 25 mA IOUT2 = 100mA Ripple Rejection f = 120Hz, I OUT2 = 50mA, 7V ² VIN ² 17V 60 70 dB Current Limit 105 200 mA Short Circuit Current Limit V OUT2 = 0V, VIN = 16V, IOUT1 = 0A 25 mA Reverse Current V OUT2 = 5V, VIN = 0V 100 250 µA n Enable Function (ENABLE) Input Threshold ENABLE = LOW, 7V ² V IN ² 26V 1.2 0.8 V ENABLE = HIGH, 7V ² VIN ² 26V 2.0 1.2 V Input Bias Current 0V ² V ENABLE ²5 V - 2 0 2 µ A n Protection Circuits Overtemperature Threshold (Guaranteed by Design) 150 180 ¡C

2.4V Turn On Load Dump Low VIN Line Noise, Etc. V OUT2 Short Circuit Thermal Shutdown Turn Off 14V 2.0V 0.8V 14V 26V31V 5V 5V 2.4V 5V5V VOUT2 5V 5V VOUT1 Short Circuit Typical Circuit Waveform PACKAGE LEAD # LEAD SYMBOL FUNCTION Package Lead Description 1V IN Supply voltage to IC, usually direct from battery. 2V OUT1 5V regulated output which is activated by ENABLE input. 3 Gnd Ground connection. OUT2 Standby output 5V, 100mA capability; always on. 5 ENABLE CMOS compatible input lead; switches V OUT1. When ENABLE is high, VOUT1 is active. Current Limit Peak current that can be delivered to the output. Dropout Voltage The input-output voltage differential at which the circuit ceases to regulate against further reduction in input volt- age. Measured when the output voltage has dropped 100mV from the nominal value obtained at 14V input, dropout voltage is dependent upon load current and junc- tion temperature. Input Output Differential The voltage difference between the unregulated input volt- age and the regulated output voltage for which the regula- tor will operate. Input Voltage The DC voltage applied to the input terminals with respect to ground. Line Regulation The change in output voltage for a change in the input voltage. The measurement is made under conditions of low dissipation or by using pulse techniques such that the average chip temperature is not significantly affected. Load Regulation The change in output voltage for a change in load current at constant chip temperature. Long Term Stability Output voltage stability under accelerated life-test condi- tions after 1000 hours with maximum rated voltage and junction temperature. Quiescent Current The part of the positive input current that does not con- tribute to the positive load current. i.e., the regulator ground lead current. Ripple Rejection The ratio of the peak-to-peak input ripple voltage to the peak-to-peak output ripple voltage. Short Circuit Current Limit Peak current that can be delivered by the output when forced to 0V. Temperature Stability of V OUT The percentage change in output voltage for a thermal varia- tion from room temperature to either temperature extreme.

The CS8391 is a micropower dual 5V regulator. All bias required to operate the internal circuitry is derived from the standby output, V OUT2. If this output experiences an over current situation and collapses, then VOUT1 will also collapse (see timing diagrams). If there is critical circuitry that must remain active under most conditions it should be connected to VOUT2. Any cir- cuitry that is likely to be subjected to a short circuit, e.g., circuitry outside the module, should be connected to V OUT1. Output capacitors are required for stability with the CS8391. Without them, the regulator outputs will oscillate. Actual size and type may vary depending upon the application load and temperature range. Capacitor effective series resistance (ESR) is also a factor in the IC stability. Worst- case is determined at the minimum ambient temperature and maximum load expected. Output capacitors can be increased in size to any desired value above the minimum. One possible purpose of this would be to maintain the output voltages during brief con- ditions of negative input transients that might be character- istic of a particular system. Capacitors must also be rated at all ambient temperatures expected in the system. To maintain regulator stability down to -40ûC, capacitors rated at that temperature must be used. More information on capacitor selection for Smart Regulatorsª is available in the Smart Regulator applica- tion note, Compensation for Linear Regulators. The ENABLE function controls V OUT1. When ENABLE is high, VOUT1 is on. When ENABLE is low, VOUT1 is off. The maximum power dissipation for a dual output regula- tor (Figure 1) is: PD(max) = {VIN(max)ÐVOUT1(min)}IOUT1(max)+ {VIN(max)ÐVOUT2(min)}IOUT2(max)+VIN(max)IQ (1) where: VIN(max) is the maximum input voltage, VOUT1(min) is the minimum output voltage from VOUT1, VOUT2(min) is the minimum output voltage from VOUT2, IOUT1(max) is the maximum output current for the appli- cation, IOUT2(max) is the maximum output current for the appli- cation, and IQ is the quiescent current the regulator consumes at both IOUT1(max) and IOUT2(max). Once the value of PD(max) is known, the maximum per- missible value of RQJA can be calculated: RQJA = (2) The value of RQJA can then be compared with those in the package section of the data sheet. Those packages with R QJA's less than the calculated value in equation 2 will keep the die temperature below 150¡C. In some cases, none of the packages will be sufficient to dissipate the heat generated by the IC, and an external heat sink will be required. Figure 1: Dual output regulator with key performance parameters labeled. A heat sink effectively increases the surface area of the package to improve the flow of heat away from the IC and into the surrounding air. Each material in the heat flow path between the IC and the outside environment will have a thermal resistance. Like series electrical resistances, these resistances are summed to determine the value of R QJA: RQJA = RQJC + RQCS + RQSA (3) where: RQJC = the junctionÐtoÐcase thermal resistance, RQCS = the caseÐtoÐheat sink thermal resistance, and RQSA = the heat sinkÐtoÐambient thermal resistance. RQJC appears in the package section of the data sheet. Like RQJA, it too is a function of package type. RQCS and RQSA are functions of the package type, heat sink and the interface between them. These values appear in heat sink data sheets of heat sink manufacturers. Heat Sinks VIN VOUT2 IIN IQ Control Features} IOUT2 VOUT1 IOUT1 Smart Regulator 150¡C - TA PD Calculating Power Dissipation in a Dual Output Linear Regulator ENABLE External Capacitors General CS8391 Application Notes

Test & Application Circuit ENABLE VIN VOUT1 CS8391 Gnd 22mF ESR<8W VCC I/O mP Gnd Load 0.1mF VBATT C2C1 VOUT2 22mF ESR<8W * C1 required if regulator is located far from power supply filter. ** C2 and C3 required for stability. Capacitor must operate at minimum temperature expected during system operations.

CS8391YDPR5 5 Lead D 2PAK (tape & reel) 6Rev. 1/12/98 © 1999 Cherry Semiconductor Corporation CS8391

Ordering Information

Thermal Data 5 Lead D 2 PAK RQJC typ 2.4 ¡C/W RQJA typ 10-50* ¡C/W * Depending on thermal properties of substrate. RQJA = RQJC + RQCA Package Specification PACKAGE THERMAL DATAPACKAGE DIMENSIONS IN MM(INCHES) Cherry Semiconductor Corporation reserves the right to make changes to the specifications without notice. Please contact Cherry Semiconductor Corporation for the latest available information.

5 Lead D2PAK (DP)

1.70 (.067) REF 0.10 (.004) 0.00 (.000) 10.31 (.406) 10.05 (.396) 0.91 (.036) 0.66 (.026) 1.40 (.055) 1.14 (.045) 4.57 (.180) 4.31 (.170) 1.68 (.066) 1.40 (.055) 2.74(.108) 2.49(.098) .254 (.010) REF 2.79 (.110) 2.29 (.090) 15.75 (.620) 14.73 (.580) 8.53 (.336) 8.28 (.326)