CS8135 CS8135 5V, 5V Low Dropout Dual Regulator with RESET /ENABLE Description Features transients, such as a 60V load dump, the 500mA output will automatically shut down the primary output to protect both internal circuits and the load. The standby regulator will continue to power any standby load. The CS8135 is a low dropout, high current, dual 5V linear regulator. The secondary 5V/10mA output is often used for powering systems with standby memory. Quiescent current drain is less than 3mA when supplying 10mA loads from the standby regulator. The CS8135 is packaged in a 5 lead TO-220. In automotive applications, the CS8135 and all regulated circuits are protected from reverse battery installations, as well as two-battery jumps. During line NOTE: The CS8135 is compatible with the LM2935. Absolute Maximum Ratings Input Voltage Operating Range .....................................................................-0.5V to 26V Load Dump ............................................................................................60V Internal Power Dissipation ..................................................Internally Limited Junction Temperature Range (TJ)............................................-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 Electrostatic Discharge (Human Body Model) ..........................................2kV ■ Two Regulated Outputs Primary Output 5V ± 5%; 500mA Secondary Standby 5V ±5%; 10mA ■ Low Dropout Voltage (0.6V at 0.5A) ■ ON/OFF Control Option ■ Low Quiescent Drain (<3mA) ■ RESET Option ■ Protection Features Reverse Battery 60V Load Dump -50V Reverse Transient Short Circuit Thermal Shutdown Overvoltage Shutdown Package Option Block Diagram 5 Lead TO-220 Standby Output V IN V OUT2 Bandgap Reference Output Current Limit + - Primary Output Gnd Thermal Shutdown RESET/ ENABLE Tab (Gnd) V OUT1 Over Voltage Shutdown + + - - Output Current Limit 1 + - 1 VIN 2 VOUT1 3 Gnd 4 RESET / ENABLE 5 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. 10/21/97 1 A ¨ Company CS8135 Electrical Characteristics : VIN = 14V, IOUT1 = 5mA, IOUT2 = 1mA, -40¡C ² TA ² 125¡C, -40¡C ² TJ ² 150¡C unless otherwise specified PARAMETER TEST CONDITIONS MIN TYP MAX UNIT ■ Output Stage (VOUT1) Output Voltage, VOUT1 6V ² VIN ² 26V, 5mA ² IOUT1 ² 500mA Dropout Voltage IOUT = 500mA IOUT = 750mA Line Regulation 5.00 5.25 V 0.35 0.50 0.60 V V 6V ² VIN ² 26V, IOUT1 = 5mA 10 50 mV Load Regulation 5mA ² IOUT ² 500mA 10 50 mV Quiescent Current IOUT1 ² 10mA, No Load on Standby IOUT1 = 500mA, No Load on Standby IOUT1 = 750mA, No Load on Standby 3 30 60 7 100 150 mA mA mA Ripple Rejection f = 120Hz 66 dB Current Limit 4.75 1.40 A Maximum Line Transient VOUT1 ² 5.5V 0.75 90 V Reverse Polarity Input Voltage, DC VOUT1 ³ -0.6V, 10½ Load -50 V Reverse Polarity Input Voltage, Transient 1% Duty Cycle, t = 100ms, VOUT1 ³ -6V, 10½ Load -80 V Output Noise Voltage 10Hz-100kHz 100 µVrms 20 mV/khr 200 m½ 30 V Long Term Stability Output Impedance 500mA DC and 10mA rms, 100Hz-10kHz Overvoltage Shutdown ■ Standby Output (VOUT2) Output Voltage (VOUT2) 6V ² VIN ² 26V, 1mA ² IOUT1 ² 10mA Dropout Voltage 4.75 5.00 5.25 V IOUT2 = 10mA 0.3 0.7 V Tracking VOUT1-VOUT2 50 200 mV Line Regulation 6V ² VIN ² 26V 4 50 mV Load Regulation 1mA ² IOUT1 ² 10mA 10 50 mV 3 mA Quiescent Current IOUT ² 10mA, VOUT OFF 2 Ripple Rejection f = 120Hz 66 dB 70 mA Current Limit Output Noise Voltage 25 10Hz-100kHz Long Term Stability Output Impedance 10mA DC and 1mA rms, 100Hz-10kHz 300 µV 20 mV/khr 1 ½ ■ RESET Function RESET Output Voltage Low R1 = 20k½, VIN = 4.5V High R1 = 20k½, VIN = 14V RESET Output Current ON/OFF Resistor See Test & Application Circuit (page 6) VIN = 4.5V, RESET in Low State R1 (±10% Tolerance) 2 4.5 0.8 5.0 1.1 6.0 5 20 V V mA 30 k½ CS8135 Package Lead Description PACKAGE LEAD # LEAD SYMBOL FUNCTION TO-220 Supply voltage to IC, usually direct from battery. 1 VIN 2 VOUT1 3 Gnd 4 RESET/ENABLE 5 VOUT2 Regulated output voltage 5V, 500mA (typ) switched. Ground connection. CMOS compatible output lead, RESET goes low whenever VOUT1 becomes unregulated. To use the ENABLE option, connect the lead via a resistor to VIN (see app. notes). STANDBY output 5V, 10mA typ, always on. 1.0 7 0.9 6 0.8 5 OUTPUT VOLTAGE (V) INPUT-OUTPUT DIFFERENTIAL VOLTAGE (V) Typical Performance Characteristics 0.7 0.6 0.5 0.4 0.3 RL=500W 4 3 2 1 0 0.2 -1 0.1 -2 0.0 0 200 400 600 -40 800 -20 20 40 60 Standby Output Voltage vs. Input Voltage Dropout Voltage vs. Output Current 20 OUTPUT VOLTAGE DEVIATION (mV) 1.0 INPUT-OUTPUT DIFFERENTIAL VOLTAGE (V) 0 INPUT VOLTAGE (V) OUTPUT CURRENT (mA) 0.9 0.8 0.7 0.6 INPUT VOLTAGE CHANGE (V) 0.5 0.4 0.3 0.2 0.1 IOUT1=500mA 10 0 -10 -20 3 2 1 0 0.0 0 5 10 15 0 20 10 20 OUTPUT CURRENT (mA) OUTPUT VOLTAGE DEVIATION (mV) 7 RL=10W 5 4 3 50 40 50 60 10 5 0 -5 -10 2 INPUT VOLTAGE CHANGE (V) OUTPUT VOLTAGE (V) 40 Line Transient Response (VOUT1) Standby Dropout Voltage vs. Output Current 6 30 TIME (ms) 1 0 -1 -2 -40 -20 0 20 40 60 3 2 1 0 0 10 INPUT VOLTAGE (V) 20 30 TIME (ms) Output Voltage vs. Input Voltage Line Transient Response (VOUT2) 3 60 CS8135 Typical Performance Characteristics: continued OUTPUT VOLTAGE DEVIATION (mV) 150 5 SWITCH OPEN VO OFF 100 QUIESCENT CURRENT (mA) 50 0 -50 -100 -150 LOAD CURRENT (A) 0.8 0.6 0.4 4 3 2 1 0.2 0 0 0 10 20 30 40 50 0 60 20 100 18 50 16 POWER DISSIPATION (W) 150 0 -50 -100 -150 20 15 10 INFINITE HEAT SINK 14 12 10 8 10° C/W HEAT SINK 6 4 NO HEAT SINK 2 5 0 0 0 10 20 30 40 50 0 60 10 20 30 40 50 60 AMBIENT TEMPERATURE (°C) TIME (ms) Maximum Power Dissipation (TO-220) Load Transient Response (VOUT2) 120 QUIESCENT CURRENT (mA) IOUT2=10mA 100 80 60 40 20 0 0 25 Quiescent Current vs. Standby Output Current Load Transient Response (VOUT1) STANDBY OUTPUT VOLTAGE DEVIATION (mV) 20 STANDBY OUTPUT CURRENT (mA) TIME (ms) STANDBY LOAD CURRENT (mA) 15 10 5 200 400 600 800 OUTPUT CURRENT (mA) Quiescent Current vs. Output Current 4 70 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 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. Current Limit Peak current that can be delivered to the output. Typical Circuit Waveform 60V SWITCH 26V 31V VIN 14V 14V 3V CLOSED OPEN 5V OPEN 5V 5V 5V 2.4V VOUT1 0V 0V 0V 5V RESET 0V VOUT2 5V System Condition 5V 5V 2.4V Turn On Load Dump Low VIN Line, Noise, Etc. VOUT1 Short Circuit Thermal Shutdown Turn Off *Reference Test & Application Circuit Circuit Description 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 diode zener, the current through the external resistor should be sufficient to bias VOUT2 up to this point. Approximately 60µA will suffice, resulting in a 10k½ external resistor for most applications. Standby Output The CS8135 is equipped with two outputs. The second output is intended for use in systems requiring standby memory circuits. While the high current regulator output can be controlled with the RESET 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. The standby regulator circuit is designed so that the quiescent current to the IC is very low (<3mA) when the other regulator output is off. 5 CS8135 Definition of Terms CS8135 Circuit Description: continued output voltage of this lead is high (5V). This is set by an internal clamp. If the high current output becomes unregulated for any reason (line transients, short circuit, thermal shutdown, low input voltage, etc.) the lead switches to the active low state, and is capable of sinking several milliamps. This output signal can be used to initiate any reset or start-up procedure that may be required of the system. VIN RD 10kW VOUT2 VOUT2 + The RESET lead can also be driven directly from logic circuits. The only requirement is that the 20k½ pull-up resistor remain in place. This will not affect the logic gate since the voltage on this lead is limited by the internal clamp to 5V. The RESET signal is sacrificed in this arrangement since the maximum sink capability of the lead in the active low state (approximately 5mA), is usually not sufficient to pull down the active high logic gate. The flag can be retained if the driving gate is open collector logic. C3 Disabling VOUT2 when it is not needed. C3 is no longer needed. High Current Output VIN 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. R1 20kW CS8135 RESET/ ENABLE Controlling ON/OFF Terminal with a typical CMOS or TTL Logic Gate R1 20kW RESET Function The RESET function has the ability to serve a dual purpose if desired. When controlled in the manner shown in the test circuit (common in automotive systems where RESET /ENABLE is connected to the ignition switch), the lead also serves as an output flag that is active low whenever a fault condition is detected with the high current regulated output. Under normal operating conditions, the CMOS MM 74CO4 or Equivalent Delayed Reset Out R2 100kW CS8135 RESET/ ENABLE Gnd 4.7 mF Reset Pulse on Power-Up (with approximately 300ms delay) Application Notes Test & Application Circuit C1* 0.1 mF S1 ON/OFF VIN Stability Considerations VOUT1 + R1 20kW RESET FLAG RESET/ ENABLE 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 output capacitor C2 shown in the test and applications circuit should work for most applications, however it is not necessarily the optimized solution. To determine acceptable values for C2 and C3 for a particular application, start with a tantalum capacitor of the rec- C2 ** 10mF CS8135 VOUT2 Gnd + C3** 10mF NOTES: * C1 required if regulator is located far from power supply filter. ** C2, C3 required for stability. 6 VOUT2(min) is the minimum output voltage from VOUT2, ommended 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 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 and 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. 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, 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 capacitor 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. 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). Once the value of PD(max) is known, the maximum permissible 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 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. IIN VIN Smart Regulator } IOUT1 VOUT1 IOUT2 VOUT2 Control Features IQ Figure 1: Dual output regulator with key performance parameters labeled. 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 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. 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 150¡C - TA PD (1) Where VIN(max) is the maximum input voltage, VOUT1(min) is the minimum output voltage from VOUT1, 7 CS8135 Application Notes: continued CS8135 Package Specification Package Dimensions in MM (Inches) PACKAGE THERMAL DATA Thermal Data RQJC typ 5 Lead TO-220 (T) Straight RQJA 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 2.3 typ 50 ûC/W ûC/W 5 Lead TO-220 (THA) Horizontal 3.96 (.156) 3.71 (.146) 4.83 (.190) 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 CS8135YT5 CS8135YTVA5 CS8135YTHA5 Rev. 10/21/97 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