CS8164 CS8164 8V/5V Low Dropout Dual Regulator with ENABLE Description The CS8164 is a low dropout, dual 8V/5V linear regulator. The secondary 5V/100mA output is used for powering systems with standby memory. Quiescent current drain is less than 2mA when supplying 10mA loads from the standby regulator. In automotive applications, the CS8164 and all regulated circuits are protected from reverse battery installations, as well as high voltage transients. During line transients, such as a 60V load dump, the 750mA output will automat- Features ically shutdown to protect both internal circuits and the load, while the secondary regulator continues to power any standby load. The on board ENABLE function controls the regulator's primary output. When ENABLE is in the low state, the regulator is placed in STANDBY mode where it draws 2mA (typ) quiescent current. The CS8164 is packaged in a 5-lead TO-220, with copper tab for connection to a heat sink, if necessary. Absolute Maximum Ratings DC Input Voltage .............................................................................-0.5V to 26V Transient Peak Voltage (46V Load Dump) .................................................60V Internal Power Dissipation ..................................................Internally Limited Operating Temperature Range................................................-40¡C to +125¡C Junction Temperature Range...................................................-40¡C to +150¡C Storage Temperature Range ....................................................-65¡C to +150¡C Reverse Polarity VOUT1 Input Voltage, DC ................................................-18V Reverse Polarity Input Voltage, Transient ................................................-50V Lead Temperature Soldering Wave Solder (through hole styles only)..........10 sec. max, 260¡C peak Block Diagram ■ Two Regulated Outputs Primary Output 8V ±5%; 750mA Secondary Output 5V ±2%; 100mA ■ Low Dropout Voltage ■ ON/OFF Control Option ■ Standby Quiescent Drain (<2mA) ■ Protection Features Reverse Battery 60V Peak Transient Voltage -50V Reverse Transient Short Circuit Thermal Shutdown Package Options 5 Lead TO-220 Tab (Gnd) Standby Output V IN ENABLE V OUT2 Output Current Limit + + - Bandgap Reference Primary Output Gnd Thermal Shutdown V OUT1 Over Voltage Shutdown + - Output Current Limit 1 1 2 3 4 5 VIN VOUT1 Gnd ENABLE VOUT2 Cherry Semiconductor Corporation 2000 South County Trail, East Greenwich, RI 02818 Tel: (401)885-3600 Fax: (401)885-5786 Email: [email protected] Web Site: www.cherry-semi.com Rev. 2/17/98 1 A ¨ Company CS8164 Electrical Characteristics for VOUT: VIN = 14V, IOUT = 500mA, -40¡C ² TJ ² +150ûC unless otherwise specified PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 7.6 7.6 8.0 8.0 8.4 8.4 V V 0.60 V mV ■ OUTPUT STAGE (VOUT1) Output Voltage, VOUT1 13V ² VIN ² 26V, IOUT1 ² 500mA, 13V ² VIN ² 16V, IOUT1 ² 750mA Dropout Voltage IOUT1 = 500mA Line Regulation 13V ² VIN ² 16V, IOUT1 = 5mA 15 80 Load Regulation 5mA ² IOUT1 ² 500mA 15 80 mV Quiescent Current IOUT1 ² 10mA, No Load on Standby IOUT1 = 500mA, No Load on Standby IOUT1 = 750mA, No Load on Standby 3 40 90 7 100 mA mA mA Ripple Rejection f = 120Hz 53 Current Limit 0.75 Long Term Stability Output Impedance 500mA DC and 10mA rms, 100Hz - 10kHz 1.40 dB 2.50 A 50 mV/khr 200 m½ Thermal Shutdown 150 190 ¡C Overvoltage Shutdown 26 40 V 4.75 5.00 5.25 V 0.55 0.70 V ■ Standby Output (VOUT2) Output Voltage, (VOUT2) 6V ² VIN ² 26V Dropout Voltage IOUT2 ² 100mA Line Regulation 6V ² VIN ² 26V 4 50 mV Load Regulation 1mA ² IOUT2 ² 100mA 10 50 mV Quiescent Current IOUT2 ² 10mA, -40ûC ² TJ ² +125ûC VOUT1 OFF 2 3 mA Ripple Rejection f = 120Hz 66 dB Current Limit 200 mA Long Term Stability 20 mV/khr 1 ½ Output Impedance 10mA DC and 1mA rms, 100Hz - 10kHz ■ ENABLE Function (ENABLE) Input ENABLE Threshold Input ENABLE Current VOUT1 Off VOUT1 On 2.00 VENABLE ² VTHRESHOLD -10 1.25 1.25 0.80 V V 10 µA Package Lead Description PACKAGE LEAD # LEAD SYMBOL FUNCTION 5 Lead TO-220 1 VIN Supply voltage, usually direct from battery. 2 VOUT1 Regulated output 8V, 750mA (typ). 3 Gnd Ground connection. 4 ENABLE CMOS compatible input lead; switches VOUT1 on and off. When ENABLE is high, VOUT1 is active. 5 VOUT2 Standby output 5V, 100mA (typ); always on. 2 CS8164 Typical Performance Characteristics Output Voltage vs. Input Voltage 1.0 0.9 0.8 0.7 OUTPUT VOLTAGE (V) INPUT-OUTPUT DIFFERENTIAL VOLTAGE (V) Dropout Voltage vs. Output Current 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 200 400 600 13 12 11 10 9 8 7 6 5 4 3 2 1 0 -1 -2 800 RL=10W -40 0 20 40 60 INPUT VOLTAGE (V) OUTPUT CURRENT (mA) Line Transient Response (VOUT1) Standby Output Voltage vs. Input Voltage 7 OUTPUT VOLTAGE DEVIATION (mV) 20 6 RL= 500W 5 4 3 2 INPUT VOLTAGE CHANGE (V) OUTPUT VOLTAGE (V) -20 1 0 -1 IOUT1 = 500mA 10 0 -10 -20 3 2 1 0 -2 -40 -20 0 20 40 60 0 INPUT VOLTAGE (V) OUTPUT VOLTAGE DEVIATION (mV) INPUT VOLTAGE CHANGE (V) 10 5 0 -5 -10 3 2 1 0 10 20 30 20 TIME (ms) Line Transient Response (VOUT2) 0 10 40 50 60 TIME (ms) 3 30 40 50 60 CS8164 Typical Performance Characteristics Load Transient Response (VOUT1) Load Transient Response (VOUT2) 150 STANDBY OUTPUT VOLTAGE DEVIATION (mV) OUTPUT VOLTAGE DEVIATION (mV) 150 100 50 0 -50 -100 50 0 -50 -100 -150 STANDBY LOAD CURRENT (mA) LOAD CURRENT (A) -150 100 0.8 0.6 0.4 0.2 20 15 10 5 0 0 0 10 20 30 40 50 60 0 10 TIME (ms) 30 40 50 60 TIME (ms) Quiescent Current vs. Output Current Maximum Power Dissipation (TO-220) 20 120 ISTBY=10mA 18 100 POWER DISSIPATION (W) QUIESCENT CURRENT (mA) 20 80 60 40 20 INFINITE HEAT SINK 16 14 12 10 8 10°C/W HEAT SINK 6 4 NO HEAT SINK 2 0 0 0 200 400 600 800 0 10 20 30 40 50 60 70 AMBIENT TEMPERATURE (°C) OUTPUT CURRENT (mA) 4 80 90 Dropout Voltage The input-output voltage differential at which the circuit ceases to regulate against further reduction in input voltage. Measured when the output voltage has dropped 100mV from the nominal value obtained at 14V input, dropout voltage is dependent upon load current and junction temperature. Long Term Stability Output voltage stability under accelerated life-test conditions after 1000 hours with maximum rated voltage and junction temperature. Output Noise Voltage The rms AC voltage at the output, with constant load and no input ripple, measured over a specified frequency range. Input Voltage The DC voltage applied to the input terminals with respect to ground. Quiescent Current The part of the positive input current that does not contribute to the positive load current. i.e., the regulator ground lead current. Input Output Differential The voltage difference between the unregulated input voltage and the regulated output voltage for which the regulator will operate. Ripple Rejection The ratio of the peak-to-peak input ripple voltage to the peak-to-peak output ripple voltage. 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. Temperature Stability of VOUT The percentage change in output voltage for a thermal variation from room temperature to either temperature extreme. Current Limit Peak current that can be delivered to the output. Load Regulation The change in output voltage for a change in load current at constant chip temperature. Typical Circuit Waveform 60V VIN 14V ENABLE 2.0V 0.8V 26V 31V 14V 3V 8V 8V 8V 8V 8V 2.4V 0V VOUT1 0V VOUT2 5V System Condition 0V 5V 5V 2.4V Turn On Load Dump Low VIN Line Noise, Etc. VOUT2 Short Circuit Thermal Shutdown Turn Off Circuit Description The standby regulator circuit is designed so that the quiescent current to the IC is very low (<2mA) when the other regulator output is off. In applications where the standby output is not needed, it may be disabled by connecting a resistor from the standby output to the supply voltage. This eliminates the need for a capacitor on the output to prevent unwanted oscillations. The value of the resistor depends upon the minimum input voltage expected for a given system. Since the standby output is shunted with an internal 6.0V Zener, the current through the external resistor should be sufficient Standby Output The CS8164 is equipped with two outputs. The second output is intended for use in systems requiring standby memory circuits. While the high current primary output can be controlled with the ENABLE lead described below, the standby output remains on under all conditions as long as sufficient input voltage is applied to the IC. Thus, memory and other circuits powered by this output remain unaffected by positive line transients, thermal shutdown, etc. 5 CS8164 Definition of Terms CS8164 Circuit Description: continued to bias VOUT2 up to this point. Approximately 60µA will suffice, resulting in a 10k½ external resistor for most applications. VIN High Current Output RD 10kW Unlike the standby regulated output, which must remain on whenever possible, the high current regulated output is fault protected against overvoltage and also incorporates thermal shutdown. If the input voltage rises above approximately 30V (e.g., load dump), this output will automatically shutdown. This protects the internal circuitry and enables the IC to survive higher voltage transients than would otherwise be expected. Thermal shutdown is effective against die overheating since the high current output is the dominant source of power dissipation in the IC. VOUT2 VOUT2 + C3 Disabling VOUT2 when it is not needed. C3 is no longer needed. ENABLE The enable function controls VOUT1 When ENABLE is high (5V), VOUT1 is on. When ENABLE is low, VOUT1 is off. Test & Application Circuit C1 * 0.1 mF VIN VOUT1 + C2** 10mF CS8164 ENABLE Gnd VOUT2 + C3** 10mF NOTES: * C1 required if regulator is located far from power supply filter. ** C2, C3 required for stability. Application Notes To determine acceptable values for C2 and C3 a particular application, start with a tantalum capacitor of the recommended value and work towards a less expensive alternative part for each output. Step 1: Place the completed circuit with the tantalum capacitors of the recommended values in an environmental chamber at the lowest specified operating temperature and monitor the outputs with an oscilloscope. A decade box connected in series with the capacitor C2 will simulate the higher ESR of an aluminum capacitor. Leave the decade box outside the chamber, the small resistance added by the longer leads is negligible. Step 2: With the input voltage at its maximum value, increase the load current slowly from zero to full load on the output under observation. look for oscillations on the output. If no oscillations are observed, the capacitor is large enough to ensure a stable design under steady state conditions. Stability Considerations The output or compensation capacitor helps determine three main characteristics of a linear regulator: start-up delay, load transient response and loop stability. The capacitor value and type should be based on cost, availability, size and temperature constraints. A tantalum or aluminum electrolytic capacitor is best, since a film or ceramic capacitor with almost zero ESR can cause instability. The aluminum electrolytic capacitor is the least expensive solution, but, if the circuit operates at low temperatures (-25¡C to -40¡C), both the value and ESR of the capacitor will vary considerably. The capacitor manufacturers data sheet usually provides this information. The value for each output capacitor shown in the test and applications circuit should work for most applications, however it is not necessarily the optimized solution. 6 CS8164 Application Notes: continued Step 3: Increase the ESR of the capacitor from zero using the decade box and vary the load current until oscillations appear. Record the values of load current and ESR that cause the greatest oscillation. This represents the worst case load conditions for the output at low temperature. Step 4: Maintain the worst case load conditions set in step 3 and vary the input voltage until the oscillations increase. This point represents the worst case input voltage conditions. Step 5: If the capacitor is adequate, repeat steps 3 and 4 with the next smaller valued capacitor. A smaller capacitor will usually cost less and occupy less board space. If the output oscillates within the range of expected operating conditions, repeat steps 3 and 4 with the next larger standard capacitor value. Step 6: Test the load transient response by switching in various loads at several frequencies to simulate its real working environment. Vary the ESR to reduce ringing. Step 7: Remove the unit from the environmental chamber and heat the IC with a heat gun. Vary the load current as instructed in step 5 to test for any oscillations. Once the minimum capacitor value with the maximum ESR is found for each output, a safety factor should be added to allow for the tolerance of the capacitor and any variations in regulator performance. Most good quality aluminum electrolytic capacitors have a tolerance of +/20% so the minimum value found should be increased by at least 50% to allow for this tolerance plus the variation which will occur at low temperatures. The ESR of the capacitors should be less than 50% of the maximum allowable ESR found in step 3 above. Repeat steps 1 through 7 with the capacitor on the other output, C3. IIN VIN } IOUT1 VOUT1 IOUT2 VOUT2 Control Features IQ Figure 1: Dual output regulator with key performance parameters labeled. Once the value of PD(max) is known, the maximum permissible value of RQJA can be calculated: RQJA = 150¡C - TA PD (2) The value of RQJA can then be compared with those in the package section of the data sheet. Those packages with RQJA'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 heatsink will be required. Heat Sinks 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. Calculating Power Dissipation in a Dual Output Linear Regulator The maximum power dissipation for a dual output regulator (Figure 1) is: PD(max) = {VIN(max) - VOUT1(min)}IOUT1(max)+ {VIN(max) - VOUT2(min)}IOUT2(max)+VIN(max)IQ Smart Regulator 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 RQJA: RQJA = RQJC + RQCS + RQSA (3) where: RQJC = the junction-to-case thermal resistance, RQCS = the case-to-heatsink thermal resistance, and RQSA = the heatsink-to-ambient 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, heatsink and the interface between them. These values appear in heat sink data sheets of heat sink manufacturers. (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 application, IOUT2(max) is the maximum output current for the application, and IQ is the quiescent current the regulator consumes at IOUT(max). 7 CS8164 Package Specification PACKAGE DIMENSIONS IN mm (INCHES) PACKAGE THERMAL DATA Thermal Data RQJC typ RQJA typ 5 Lead TO-220 (T) Straight 10.54 (.415) 9.78 (.385) 2.87 (.113) 6.55 (.258) 2.62 (.103) 5.94 (.234) ûC/W ûC/W 5 Lead TO-220 (THA) Horizontal 1.40 (.055) 1.14 (.045) 4.83 (.190) 4.06 (.160) 5 Lead TO-220 2.0 50 4.83 (.190) 10.54 (.415) 9.78 (.385) 3.96 (.156) 3.71 (.146) 2.87 (.113) 2.62 (.103) 1.40 (.055) 14.99 (.590) 14.22 (.560) 4.06 (.160) 1.14 (.045) 3.96 (.156) 3.71 (.146) 14.99 (.590) 14.22 (.560) 6.55 (.258) 5.94 (.234) 14.22 (.560) 13.72 (.540) 2.77 (.109) 6.83 (.269) 1.02 (.040) 0.76 (.030) 1.68 (.066) TYP 1.70 (.067) 0.81(.032) 1.83(.072) 1.57(.062) 1.02(.040) 0.63(.025) 0.56 (.022) 0.36 (.014) 6.93(.273) 6.68(.263) 2.92 (.115) 2.29 (.090) 0.56 (.022) 0.36 (.014) 6.60 (.260) 5.84 (.230) 6.81(.268) 2.92 (.115) 2.29 (.090) 5 Lead TO-220 (TVA) Vertical 4.83 (.190) 4.06 (.160) 10.54 (.415) 9.78 (.385) 3.96 (.156) 3.71 (.146) 1.40 (.055) 1.14 (.045) 6.55 (.258) 5.94 (.234) 2.87 (.113) 2.62 (.103) 14.99 (.590) 14.22 (.560) 1.78 (.070) 2.92 (.115) 2.29 (.090) 8.64 (.340) 7.87 (.310) 4.34 (.171) 1.68 (.066) typ 1.70 (.067) 0.56 (.022) 0.36 (.014) 7.51 (.296) 6.80 (.268) .94 (.037) .69 (.027) Ordering Information Part Number CS8164YT5 CS8164YTVA5 CS8164YTHA5 Rev. 2/17/98 Description 5 Lead TO-220 Straight 5 Lead TO-220 Vertical 5 Lead TO-220 Horizontal Cherry Semiconductor Corporation reserves the right to make changes to the specifications without notice. Please contact Cherry Semiconductor Corporation for the latest available information. 8 © 1999 Cherry Semiconductor Corporation