CS8371ETVA7

CS8371 CHERRY | Alldatasheet

Document overview

• Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 8

Technical content

Features

8V ±5%, 1A 5V ±5%, 250mA n Independent ENABLE for each Output n Separate Sense Feedback Lead for 8V Output n <10µA Sleep Mode Current n Fault Protection Overvoltage Shutdown +45V Peak Transient Voltage Short Circuit Thermal Shutdown n CMOS Compatible, Low- Current ENABLE Inputs Package Options TO-220 7 Lead Tab (Gnd) CS8371 8V/1A, 5V/250mA Dual Regulator with Independent Output Enables and NoCapª CS8371

Description

1.2V 1.2V Block Diagram The CS8371 is a 8V/5V dual output linear regulator. The 8V ±5% output sources 1A, while the 5V ±5% out- put sources 250mA. Each output is controlled by its own ENABLE lead. Setting the ENABLE input high turns on the associated regula- tor output. Holding both ENABLE inputs low puts the IC into sleep mode where current consumption is less than 10µA. The regulator is protected against overvoltage, short-circuit and ther- mal runaway conditions. The device can withstand 45V load dump transients making suitable for use in automotive environ- ments. CherryÕs proprietary NoCapª solution is the first tech- nology which allows the output to be stable without the use of an external capacitor. The CS8371 is available in a 7 lead TO-220 package with copper tab. The tab can be connected to a heatsink if necessary.

1 ENABLE

2 ENABLE2

4 Gnd

5 Sense

Rev. 6/9/99 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 A Company ¨ NoCap is a trademark of Cherry Semiconductor Corporation, and is patented.

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT IOUT1 = IOUT2 = 5.0mA, unless otherwise stated. n Primary Output (VOUT1) Output Voltage I OUT1 = 1.0A 7.60 8.00 8.40 V Line Regulation 10.5V ² V CC ² 26V 50 mV Load Regulation 5mA ² I OUT1 ² 1.0A 150 mV Sleep Mode Quiescent V CC = 14V, ENABLE1 = ENABLE2 = 0V 0 0.2 10.0 µA Current Quiescent Current V CC = 14V, IOUT1 = 1.0A, IOUT2 = 250mA 30 mA Dropout Voltage I OUT1 = 250mA 1.2 V Dropout Voltage I OUT1 = 1.0A 1.5 V Quiescent Bias Current I OUT1 = 5mA, ENABLE2 = 0V, VCC = 14V 10 mA IQ = ICC - IOUT1 Quiescent Bias Current I OUT1 = 1.0A, ENABLE2 = 0V, VCC = 14V 22 mA IQ = ICC - IOUT1 Ripple Rejection f = 120Hz, V CC = 14V with 1.0VPP AC, 90 dB COUT = 0µF f = 10kHz, VCC = 14V with 1.0VPP AC, 74 dB COUT = 0µF f = 20kHz, VCC = 14V with 1.0VPP AC, 68 dB COUT = 0µF Current Limit V CC = 16V 1.1 2.5 A Overshoot Voltage 5mA ² I REG1 ² 1.0A 6.0 V Output Noise 10Hz-100kHz 300 µV rms n Secondary Output (VOUT2) Output Voltage I OUT2 = 250mA 4.75 5.00 5.25 V Line Regulation 7V ² V CC ² 26V 40 mV Load Regulation 5mA ² I OUT2 ² 250mA 100 mV Dropout Voltage I OUT2 = 5.0mA 2.2 V Dropout Voltage I OUT2 = 250mA 2.5 V Quiescent Bias Current I OUT2 = 5mA, ENABLE1 = 0V, VCC = 14V 7 mA IQ = ICC - IOUT2 Quiescent Bias Current I OUT2 = 250mA, ENABLE1 = 0V, VCC = 14V 8 mA IQ = ICC - IOUT2 Ripple Rejection f = 120Hz, V CC = 14V with 1.0 VPP AC, 90 dB COUT = 0µF f= 10kHz, VCC = 14V with 1.0VPP AC, 75 dB COUT = 0µF f = 20kHz, VCC = 14V with 1.0VPP AC, 67 dB COUT = 0µF Absolute Maximum Ratings

IOUT1 = IOUT2 = 5.0mA, unless otherwise stated. CS8371 Package Pin Description PACKAGE PIN # PIN SYMBOL FUNCTION

7 Lead TO-220

1 ENABLE 1 ENABLE control for the 8V, 1A output

2 ENABLE 2 ENABLE control for the 5V, 250mA output

3V OUT2 5V ±5%, 250mA regulated output

4 Gnd Ground

5 Sense Sense feedback for the primary 8V output

CC Supply voltage, usually from battery 7V OUT1 8V ±5%, 1A regulated output PARAMETER TEST CONDITIONS MIN TYP MAX UNIT n Secondary Output (VOUT2): continued Current Limit V CC = 16V 270 600 mA Overshoot Voltage 5mA ² I REG2 ² 250mA 4.3 V Output Noise 10Hz-100kHz 170 µV rms n ENABLE Function (ENABLE) Input Current V CC = 14V, 0V ² ENABLE ² 5.5V -150 150 µA Input Voltage Low 0 0.8 V High 2.0 5.0 V n Protection Circuitry ESD Threshold Human Body Model ±2.0 ±4.0 kV Overvoltage Shutdown 24 30 V Thermal Shutdown Guaranteed by Design 150 180 ¡C Thermal Hysteresis 30 ¡C Typical Performance Characteristics Output Voltage (V) 8.05 8.04 8.03 8.02 8.01 8.00 7.99 7.98 7.97 7.96 7.95-40 -20 0 20 40 60 80 100 120 140 Ambient Temperature (°C) VIN = 14V IOUT = 1A Regulator 1 Output Voltage Regulator 2 Output Voltage Output Voltage (V) -40 -20 0 20 40 60 80 100 120 140 Ambient Temperature (°C) 5.00 4.95 4.90 4.85 VIN = 14V IOUT = 250A Dropout Voltage (V) 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 00 100 200 300 400 500 600 700 800 900 Output Current (mA) 1000 -40°C 25°C 85°C Regulator 1 Dropout Voltage

Typical Performance Characteristics: continued Dropout Voltage (V) 2.5 2.0 1.5 1.0 0.5 00 50 100 150 200 Output Current (mA) 250 -40°C 25°C 85°C Regulator 2 Dropout Voltage Regulator 1 Current Limit Reg 1 Output Voltage (V) 0 012 Reg 1 Output Current (A) VIN = 14V TA = 25°C Reg 2 Output Voltage (V) 00 100 200 Reg 2 Output Current (mA) 300 VIN = 14V TA = 25°C 400 500 Regulator 2 Current Limit Quiescent Current (mA) 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0-40 -2 00 2 04 06 08 0 Ambient Temperature (°C) Enable 1 = 5V Enable 2 = 5V V IN = 14V IOUT 1 = 1A IOUT 2 = 250mA Quiescent Current Quiescent Current Quiescent Current (mA) 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0-40 -2 00 2 04 06 08 0 Ambient Temperature (°C) Enable 1 = 0V Enable 2 = 0V V IN = 14V Quiescent Current (mA) 6.0 5.5 5.0 4.5 4.0 3.5 3.0-40 -2 00 2 04 06 08 0 Ambient Temperature (°C) IOUT = 5mA IOUT = 1A Enable 1 = 5V Enable 2 = 0V V IN = 14V Regulator 1 Quiescent Current Quiescent Current (mA) 4.0 3.8 3.6 3.4 3.2 3.0 2.8 2.6 2.4 2.2 2.0-40 -2 00 2 04 06 08 0 Ambient Temperature (°C) IOUT = 5mA IOUT = 250mA Enable 1 = 0V Enable 2 = 5V V IN = 14V Regulator 2 Quiescent Current Regulator 1 Load Regulation Output Voltage (V) 8.020 8.015 8.010 8.005 8.000 7.995 7.990 7.985 7.9800 100 200 300 400 500 600 700 800 900 Output Current (mA) 1000 85°C 25°C -40°C VIN = 14V Output Voltage (V) 5.02 5.01 5.00 4.99 4.98 4.97 4.96 4.95 4.940 50 100 150 200 Output Current (mA) 250 -40°C 25°C 85°C VIN = 14V Regulator 2 Load Regulation Enable 1 (V) Time (ms) 23456789 1 0 1 1 1 2 Reg 1 Output Voltage (V) COUT = 0mF TA = 25°C IOUT = 5mA Regulator 1 Startup Regulator 2 Startup Enable 2 (V) Time (ms) 23456789 1 0 1 1 1 2 Reg 2 Output Voltage (V) COUT = 0mF TA = 25°C IOUT = 5mA Output Voltage Deviation (V) 0 100 200 300 400 500 Time (ns) 600 Input Voltage (V) COUT = 0mF TA = 25°C Regulator 1 Line Transient Response

Typical Performance Characteristics: continued CS8371 Output Voltage Deviation (V) 0.4 0.2 -0.2 -0.4 0 100 200 300 400 500 Time (ns) 600 Input Voltage (V) -0.6

0.6 COUT = 0mF

TA = 25°C Regulator 2 Line Transient Response Regulator 1 Load Transient Response Output Voltage Deviation (V) 1000 0 5 10 15 20 25 Time (ms) Load Current (mA)

3 VIN = 14V

COUT = 0mF TA = 25°C Output Voltage Deviation (mV) +500 -500 250 0 5 10 15 20 25 Time (ms) Load Current (mA) VIN = 14V COUT = 0mF TA = 25°C Regulator 2 Load Transient Response Ripple Rejection (dB) 100 201 10 100 1k 10k 100k Frequency (Hz) TA = 25°C VIN = 14V COUT = 0mF Regulator 1 Ripple Rejection Regulator 2 Ripple Rejection Ripple Rejection (dB) 100 201 10 100 1k 10k 100k Frequency (Hz) TA = 25°C VIN = 14V COUT = 0mF Output Capacitor ESR (W) 0.1 .01 0.1 1 10 100 1000 Output Capacitor Size (mF) Unstable Region TA = 25°C VIN = 14V RESR £ 1.6W IOUT = 5ma to 1A Regulator 1 Stability Definition of Terms 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. Current Limit: Peak current that can be delivered to the output. Input Voltage: The DC voltage applied to the input terminals with respect to ground. Input Output Differential: The voltage difference between the unregulated input voltage and the regulated output voltage for which the regulator will operate. 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 tech- niques 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 accelerat- ed 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. Quiescent Current: The part of the positive input current that does not contribute to the positive load current. 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. Temperature Stability of V OUT: The percentage change in out- put voltage for a thermal variation from room temper- ature to either temperature extreme.

With separate control of each output channel, the CS8371 is ideal for applications where each load must be switched independently. In an automotive radio, the 8V output drives the displays and tape drive motors while the 5V output supplies the Tuner IC and memory. Stability Considerations/NoCapª Normally a low dropout or quasi-low dropout regulator (or any type requiring a slow lateral PNP in the control loop) necessitates a large external compensation capacitor at the output of the IC. The external capacitor is also used to curtail overshoot, determine startup delay time and load transient response. Traditional LDO regulators typically have low unity gain bandwidth, display overshoot and poor ripple rejection. Compensation is also an issue because the high frequency load capacitor value, ESR (Equivalent Series Resistance) and board layout parasitics all can create oscillations if not properly accounted for. NoCapª is a Cherry Semiconductor exclusive output stage which internally compensates the LDO regulator over temperature, load and line variations without the need for an expensive external capacitor. It incorporates high gain (>80dB) and large unity gain bandwidth (>100kHz) while maintaining many of the characteristics of a single-pole amplifier (large phase margin and no overshoot). NoCapª is ideally suited for slow switching or steady loads. If the load displays large transient current require- ments, such as with high frequency microprocessors, an output storage capacitor may be needed. Some large capacitor and small capacitor ESR values at the output may cause small signal oscillations at the output. This will depend on the load conditions. With these types of loads, a traditional output stage may be better suited for proper operation. Output 1 employs NoCapª. Refer to the plots in the Typical Performance Characteristics section for appropri- ate output capacitor selections for stability if an external capacitor is required by the switching characteristics of the load. Output 2 has a Darlington NPN-type output struc- ture and is inherently stable with any type of capacitive load or no capacitor at all. Applications Circuit Application Notes CS8371 C1* 0.1 mF ENABLE1 VIN VOUT1 Gnd VOUT2 Control DISPLAY Tuner IC ENABLE2 CS8371 *C1 is required if regulator is far from power source filter.

Applications Notes: continued CS8371 Calculating Power Dissipation in a Dual Output Linear Regulator The maximum power dissipation for a dual output regu- lator (Figure 1) is PD(max) = {VIN(max) Ð VOUT1(min)}IOUT1(max) + {VIN(max) Ð VOUT2(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, IQ is the quiescent current the regulator consumes at IOUT(max). Once the value of PD(max) is known, the maximum permis- sible 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 RQ JA'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. Heatsinks A heatsink 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 RQ JA: 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 inter- face between them. These values appear in heatsink data sheets of heatsink manufacturers. 150¡C - T A PD VIN VOUT2 IIN IQ Control Features} IOUT2 VOUT1 IOUT1 Smart Regulator Figure 1: Dual output regulator with key performance parameters labeled.

8Rev. 6/9/99 © 1999 Cherry Semiconductor Corporation CS8371 Part Number Description CS8371ET7 7 Lead TO-220 Straight CS8371ETVA7 7 Lead TO-220 Vertical Thermal Data TO-220 RQJC typ 2.4 ûC/W RQJA typ 50 ûC/W Package Specification PACKAGE THERMAL DATA Ordering Information Cherry Semiconductor Corporation reserves the right to make changes to the specifications without notice. Please contact Cherry Semiconductor Corporation for the latest available information. PACKAGE DIMENSIONS IN mm (INCHES)

7 Lead TO-220 (T) Straight

2.87 (.113) 2.62 (.103) 9.78 (.385) 10.54 (.415) 1.40 (.055) 1.14 (.045) 0.64 (.025) 0.38 (.015) 0.56 (.022) 0.36 (.014) 1.40 (.055) 1.14 (.045) 4.83 (.190) 4.06 (.160) 14.22 (.560) 13.72 (.540) 0.94 (.037) 0.58 (.023) 7.75 (.305) 7.49 (.295) 2.92 (.115) 2.29 (.090) 3.71 (.146) 14.22 (.560) 6.55 (.258) 5.94 (.234)

7 Lead TO-220 (TVA) Vertical

10.54 (.415) 9.78 (.385) 2.03 (.080) 7.52 (.296) 4.34 (.171) 1.40 (.055) 1.14 (.045) 14.99 (.590) 14.22 (.560) 11.86 (.467) 4.83 (.190) 4.06 (.160) 8.26 (.325) 7.62 (.300) 0.81 (.030) 1.27 (.050) TYP 0.56 (.022) 0.36 (.014) 2.92 (.115) 2.29 (.090) 2.87 (.113) 2.62 (.103) 6.55 (.258) 5.94 (.234) 2.92 (.115) 3.96 (.156) 3.71 (.146)