CS8156 CS8156 12V, 5V Low Dropout Dual Regulator with ENABLE Features Description The CS8156 is a low dropout 12V/5V dual output linear regulator. The 12V ± 5% output sources 750mA and the 5V ±2.0% output sources 100mA. The regulator is protected against overvoltage conditions. Both outputs are protected against short circuit and thermal runaway conditions. The on board ENABLE function controls the regulatorÕs two outputs. When the ENABLE lead is low, the regulator is placed in SLEEP mode. Both outputs are disabled and the regulator draws only 200nA of quiescent current. The CS8156 is packaged in a 5 lead TOÐ220 with copper tab. The copper tab can be connected to a heat sink if necessary. ■ Two regulated outputs 12V ±5.0%; 750mA 5V ±2.0%; 100mA ■ Very low SLEEP mode current drain 200nA ■ Fault Protection Reverse Battery +60V, -50V Peak Transient Voltage Absolute Maximum Ratings Input Voltage Operating Range .....................................................................-0.5V to 26V Peak Transient Voltage (Load Dump = 46V) ....................................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 Lead Temperature Soldering Wave Solder (through hole styles only)..........10 sec. max, 260¡C peak Short Circuit Thermal Shutdown ■ CMOS Compatible ENABLE Package Options Block Diagram 5 Lead TO-220 VOUT2, 5V VIN ENABLE + + Pre-Regulator - - Tab (Gnd) Anti-Saturation and Current Limit VOUT1, 12V Over Voltage Shutdown Gnd Bandgap Reference + 1 VIN Anti-Saturation and Current Limit 2 3 4 5 - 1 Thermal Shutdown 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. 2/19/98 1 A ¨ Company CS8156 Electrical Characteristics for VOUT: VIN = 14.5V, IOUT1 = 5mA, IOUT2 = 5mA, -40¡C ² TJ ² +150ûC, -40¡C ² TC ² +125ûC unless otherwise specified PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 11.2 12.0 12.8 V ■ Output Stage(VOUT1) Output Voltage, VOUT1 13V ² VIN ² 16V, IOUT1 ² 750mA Dropout Voltage IOUT1 = 500mA IOUT1 = 750mA 0.4 0.6 0.6 1.0 V V Line Regulation 13V ² VIN ² 16V ,5mA ² IOUT < 100mA 15 80 mV Load Regulation 5mA ² IOUT1 ² 500mA 15 80 mV Quiescent Current IOUT1 ² 500mA, No Load on Standby IOUT1 ² 750mA, No Load on Standby 45 100 125 250 mA mA Sleep Mode ENABLE = Low 200 nA Ripple Rejection f = 120Hz, IOUT = 5mA, VIN = 1.5VPP at 15.5VDC 42 70 dB 0.75 1.20 Current Limit 2.50 A Maximum Line Transient VOUT1 ² 13V 60 90 V Reverse Polarity Input Voltage, DC VOUT1 ³ -0.6V, 10½ Load -18 -30 V Reverse Polarity Input Voltage, Transient 1% Duty Cycle, t = 100ms, VOUT ³ -6V, 10½ Load -50 -80 V Output Noise Voltage 10Hz - 100kHz Output Impedance 500mA DC and 10mA rms, 100Hz Over-voltage Shutdown 500 µVrms 0.2 1.0 ½ 28 34 45 V 4.90 5.00 5.10 V 0.60 V ■ Standby Output (VOUT2) Output Voltage, (VOUT2) 9V ² VIN ² 16V, 1mA ² IOUT2 ² 100mA Dropout Voltage IOUT2 ² 100mA Line Regulation 6V ² VIN ² 26V; 1mA ² IOUT ² 100mA 5 50 mV Load Regulation 1mA ² IOUT2 ² 100mA; 9V ² VIN ² 16V 5 50 mV Quiescent Current VOUT1 OFF, VOUT2 OFF, VENABLE = 0.8V 1 350 µA Ripple Rejection f = 120Hz; IOUT = 100mA, VIN = 1.5VPP at 14.5VDC 42 70 dB 100 200 mA VOUT1 Off VOUT1 On 1.25 1.25 0.80 2.00 V V VENABLE ² VTHRESHOLD -10 0 10 µA Current Limit ■ ENABLE Function (ENABLE) Input ENABLE Threshold Input ENABLE Current Package Lead Description PACKAGE LEAD # LEAD SYMBOL FUNCTION 5 Lead TO-220 1 VIN Supply voltage, usually direct from battery. 2 VOUT1 Regulated output 12V, 750mA (typ) 3 Gnd Ground connection. 4 ENABLE CMOS compatible input lead; switches outputs on and off. When ENABLE is high VOUT1 and VOUT2 are active. 5 VOUT2 Regulated output 5V, 100mA (typ). 2 CS8156 Typical Performance Characteristics Dropout Voltage vs IOUT2 VOUT1 vs. Input Voltage 13 12 2000 1800 11 10 1600 9 8 7 OUTPUT VOLTAGE (V) Dropout Voltage (mV) 1400 1200 1000 800 600 400 RL=10W 6 5 4 3 2 1 0 200 -1 -2 0 0 50 100 150 -40 200 -20 IOUT (mA) VOUT1 vs. Temperature 20 40 60 VOUT2 vs. Temperature 5.030 12.15 12.10 5.020 12.05 5.010 12.00 VOUT2 (V) VOUT1 (V) 0 INPUT VOLTAGE (V) 11.95 11.90 5.000 4.990 11.85 4.980 11.80 11.75 -40 -20 0 20 40 60 80 Temp (°C) 4.970 -40 100 120 140 160 ENABLE Current vs. ENABLE Voltage -20 0 20 40 60 80 Temp (°C) 100 120 140 160 ENABLE Current vs. ENABLE Voltage 5.0 I ENABLE (mA) 100 IENABLE (mA) 80 60 4.0 3.0 40 2.0 20 1.0 0 0 1 2 3 4 0.0 0.0 5 VENABLE (V) 5 10 15 VENABLE (V) 3 20 25 CS8156 Typical Performance Characteristics: continued Line Transient Response (VOUT1) Line Transient Response (VOUT2) 10 5 OUTPUT VOLTAGE DEVIATION (mV) IOUT1 = 500mA 10 0 -10 -20 3 2 1 0 0 10 20 30 40 50 IOUT2 = 100mA 0 -5 -10 3 INPUT VOLTAGE CHANGE (V) INPUT VOLTAGE CHANGE (V) OUTPUT VOLTAGE DEVIATION (mV) 20 2 1 0 0 60 10 TIME (ms) 50 60 150 STANDBY OUTPUT VOLTAGE DEVIATION (mV) OUTPUT VOLTAGE DEVIATION (mV) 40 Load Transient Response (VOUT2) 150 100 50 0 -50 -100 100 50 0 -50 -100 -150 STANDBY LOAD CURRENT (mA) -150 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) Quiescent Current (mA) INFINITE HEAT SINK 16 14 12 10 8 10°C/W HEAT SINK 6 4 NO HEAT SINK 2 0 0 10 20 30 40 50 30 40 50 60 Quiescent Current vs Output Current for VOUT2 20 18 20 TIME (ms) Maximum Power Dissipation (TO-220) POWER DISSIPATION (W) 30 TIME (ms) Load Transient Response (VOUT1) LOAD CURRENT (A) 20 60 70 80 90 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 No Load on 5V VIN = 14V 25ûC -40ûC 0 100 200 300 400 500 Output Current (mA) AMBIENT TEMPERATURE (°C) 4 125ûC 600 700 800 CS8156 Typical Performance Characteristics: continued Quiescent Current vs Output Current for VOUT1 Line Regulation vs Output Current for VOUT2 22 3 No Load On 12V 20 2 1 16 Line Regulation (mV) Quiescent Current (mA) 18 VIN = 14V 14 12 10 8 -40ûC 6 25ûC 4 125ûC 2 0 25ûC 0 -40ûC -1 125ûC -2 -3 VIN = 6 - 26V -4 -5 -6 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Output Current (mA) 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Output Current (mA) Line Regulation vs Output Current for VOUT1 Load Regulation vs Output Current for VOUT2 0 -40ûC 25ûC -4 Line Regulation (mV) Load Regulation (mV) -2 -6 -8 -10 -12 125ûC -14 VIN = 14V -16 -18 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Output Current (mA) Load Regulation vs Output Current for VOUT1 0 -5 Load Regulation (mV) -40ûC -10 25ûC -15 125ûC -20 -25 VIN = 14V -30 -35 -40 0 100 200 300 400 500 600 Output Current (mA) 700 800 5 25 20 15 10 5 0 -5 -10 -15 -20 -25 -30 -35 -40 VIN = 13 - 26V 125ûC 25ûC -40ûC 0 100 100 100 100 100 100 Output Current (mA) 100 800 CS8156 Definition of Terms Long Term Stability Output voltage stability under accelerated life-test conditions after 1000 hours with maximum rated voltage and junction temperature. 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. Output Noise Voltages 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. 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 12V 12V 12V 12V 12V 2.4V 0V VOUT1 0V 0V 5V 5V 2.4V VOUT2 System Condition 0V Turn On Load Dump Low VIN Line Noise, Etc. VOUT1 Short Circuit VOUT2 Short Circuit VOUT 1 Thermal Shutdown Turn Off Application Notes To determine acceptable values for C2 and C3 for 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 value in an environmental chamber at the lowest specified operating temperature and monitor the outputs with an oscilloscope. A decade box connected in series with capacitor C2will 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 any 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 cheapest 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 the output capacitors C2 and C3 shown in the test and applications circuit should work for most applications, however it is not necessarily the best solution. 6 CS8156 Application Notes 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 C3, the capacitor on the other output. IIN VIN } VOUT1 IOUT2 VOUT2 Control Features IQ Figure 1: Dual output regulator with key performance parameters labeled. 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. 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 junctionÐtoÐcase thermal resistance, RQCS = the caseÐtoÐheatsink thermal resistance, and RQSA = the heatsinkÐtoÐambient 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. 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)ÐVOUT1(min)}IOUT1(max)+ {VIN(max)ÐVOUT2(min)}IOUT2(max)+VIN(max)IQ IOUT1 Smart Regulator (1) Where: VIN(max) is the maximum input voltage, Test & Application Circuit VOUT1(min) is the minimum output voltage from VOUT1, VOUT2(min) is the minimum output voltage fromVOUT2, IOUT1(max) is the maximum output current for the application, C1* 0.1mF VIN IOUT2(max) is the maximum output current for the application, and C2** 22mF + C3** 22mF ENABLE Once the value of PD(max) is known, the maximum permissible value of RQJA can be calculated: 150¡C - TA PD + CS8156 IQ is the quiescent current the regulator consumes at IOUT(max). RQJA = VOUT1 Gnd NOTES: * C1 required if regulator is located far from power supply filter. ** C2, C3 required for stability. (2) 7 VOUT2 CS8156 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) 1.40 (.055) 1.14 (.045) 4.83 (.190) 4.06 (.160) 5 Lead TO-220 2.0 50 ûC/W ûC/W 5 Lead TO-220 (THA) Horizontal 4.83 (.190) 3.96 (.156) 3.71 (.146) 10.54 (.415) 9.78 (.385) 2.87 (.113) 2.62 (.103) 14.99 (.590) 14.22 (.560) 1.40 (.055) 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) 1.83(.072) 1.57(.062) 1.02(.040) 0.63(.025) 1.68 (.066) TYP 1.70 (.067) 0.81(.032) 0.56 (.022) 0.36 (.014) 2.92 (.115) 2.29 (.090) 0.56 (.022) 0.36 (.014) 6.60 (.260) 5.84 (.230) 6.81(.268) 6.93(.273) 6.68(.263) 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 CS8156YT5 CS8156YTVA5 CS8156YTHA5 Rev. 2/19/98 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