CS5206 -1,-3,-5
CS5206 -1,-3,-5
6A Adjustable, and Fixed 3.3V and 5V Linear Regulators
Description
The CS5206 -X series of linear regulators provides 6A at adjustable and fixed voltages of 3.3V and 5V with an accuracy of ±1% and ±2% respectively. The adjustable version uses two external resistors to set the output voltage within a 1.25V to 13V range. The regulators are intended for use as post regulators and microprocessor supplies. The fast loop response and low dropout voltage make these regulators ideal for applications where low voltage operation and good transient response are important. The circuit is designed to operate with dropout voltages as low as 1V depending on the output current level. The maximum quiescent current is only 10mA at full load. The regulators are fully protected against overload conditions with protection circuitry for Safe Operating Area (SOA), overcurrent and thermal shutdown. The regulators are available in TO220 and surface mount D2 packages.
Features
s Output Current to 6A s Output Trimmed to +/- 1% s Dropout Voltage 1.3V @ 6A s Fast Transient Response s Fault Protection Circuitry Thermal Shutdown Overcurrent Protection Safe Area Protection
Block Diagram
CS5206 -1
V OUT V IN
Package Options
3L TO-220 3L D2PAK
Tab (VOUT)
Output Current Limit Thermal Shutdown + Error Amplifier Adj
Bandgap
1
CS5206 -3, -5
V OUT V IN
1
Output Current Limit Thermal Shutdown + Error Amplifier
1 2 3
CS5206 -1 Adj VOUT VIN
1 2 3
CS5206 -3, -5 Gnd VOUT VIN
Bandgap Gnd
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
Rev. 7/8/97
1
A
¨
Company
CS5206 -1,-3,-5
Absolute Maximum Ratings Supply Voltage, VCC ..................................................................................................................................................................17V Operating Temperature Range................................................................................................................................-40¡C to 70¡C Junction Temperature ............................................................................................................................................................150¡C Storage Temperature Range ..................................................................................................................................-60¡C to 150¡C Lead Temperature Soldering: Wave Solder (through hole styles only)..........................................10 sec. max, 260¡C peak Reflow (SMD styles only) ......................................................................................60 sec. max above 183¡C, 230¡C peak Electrical Characteristics: CIN = 10µF, COUT = 22µF Tantalum, VIN Ð VOUT=3V, VIN ² 15V, 0¡C ² TA ² 70¡C, TJ ² +150¡C,
unless otherwise specified, Ifull load = 6A. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
s Adjustable Output Voltage (CS5206 -1) Reference Voltage (Notes 1 and 2) Line Regulation Load Regulation (Notes 1 and 2) Dropout Voltage (Note 3) Current Limit Minimum Load Current Adjust Pin Current Adjust Pin Current Change Thermal Regulation Ripple Rejection Temperature Stability RMS Output Noise Thermal Shutdown Thermal Shutdown Hysteresis 10Hz²f²10kHz; TA=25¡C 150 1.5V²VINÐVOUT²4V; 10mA²IOUT²6A 30ms pulse; TA=25¡C f=120Hz; CAdj=25µF; IOUT=6A VINÐVOUT = 1.5V; VAdj = 0V 10mA²IOUT²6A 1.5V²VINÐVOUT²6V; IOUT=10mA VINÐVOUT=1.5V; 10mA²IOUT²6A IOUT=6A VINÐVOUT=3V; TJ ³ 25¡C VINÐVOUT=9V VINÐVOUT=7V 6.5 1.241 (-1%) 1.254 0.04 0.1 1.3 8.5 1.0 1.2 50 0.2 0.003 82 0.5 0.003 180 25 6 100 5.0 1.266 (+1%) 0.20 0.4 1.4 V % % V A A mA µA µA %W dB % %VOUT ¡C ¡C
Electrical Characteristics: CIN = 10µF, COUT = 22µF Tantalum, VIN Ð VOUT=3V, VIN ² 10V, 0¡C ² TA ² 70¡C, TJ ² +150¡C,
unless otherwise specified, Ifull load = 6A. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
s Fixed Output Voltage (CS5206 -3, -5) CS5206 -5 (Notes 1 and 2) CS5206 -3 (Notes 1 and 2) Line Regulation Load Regulation (Notes 1 and 2) Dropout Voltage (Note 3) Current Limit Quiescent Current Thermal Regulation Ripple Rejection Temperature Stability 2 VINÐVOUT = 1.5V; 0²IOU T²6A VINÐVOUT = 1.5V; 0²IOUT²6A 1.5V²VINÐVOUT ² 6V; IOUT=10mA VINÐVOUT = 1.5V; 10mA ² IOUT²6A IOUT=6A VINÐVOUT=3V; TJ ³ 25¡C VINÐVOUT=9V VIN²9V; IOUT=10mA 30ms pulse; TA=25¡C f=120Hz; IOUT=6A 6.5 4.9 (-2%) 3.234 (-2%) 5.0 3.300 0.04 0.1 1.3 8.5 1.0 5.0 0.003 75 0.5 10.0 5.1 (+2%) 3.366 (+2%) 0.20 0.4 1.4 V V % % V A A mA %/W dB %
CS5206 -1,-3,-5
Electrical Characteristics: CIN = 10µF, COUT = 22µF Tantalum, VIN Ð VOUT=3V, VIN ² 10V, 0¡C ² TA ² 70¡C, TJ ² +150¡C,
unless otherwise specified, Ifull load = 6A. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
s Fixed Output Voltage (CS5206 -3, -5) RMS Output Noise (%VOUT) Thermal Shutdown Thermal Shutdown Hysteresis 10Hz²f²10kHz 150 0.003 180 25 %VOUT ¡C ¡C
Note 1: Load regulation and output voltage are measured at a constant junction temperature by low duty cycle pulse testing. Changes in output voltage due to thermal gradients or temperature changes must be taken into account separately. Note 2: Specifications apply for an external Kelvin sense connection at a point on the output pin 1/4Ó from the bottom of the package. Note 3: Dropout voltage is a measurement of the minimum input/output differential at full load.
Package Pin Description
PACKAGE PIN # PIN SYMBOL FUNCTION
CS5206 -1 D2PAK 3L TO-220 1 2 3 N/A 1 2 3 N/A
CS5206 -3, -5 D2PAK 3L TO-220 N/A 2 3 1 N/A 2 3 1 Adj VOUT VIN Gnd Adjust pin (low side of the internal reference). Regulated output voltage (case). Input voltage. Ground connection.
Typical Performance Characteristics
1.40 1.35 1.25
Dropout Voltage (V) Output Voltage Deviation (%) 0.10 0.08 0.06 0.04 0.02 0.00 -0.02 -0.04 -0.06 -0.08 -0.10 -0.12 0 1 2 3 4 Output Current (A) 5 6 0 10 20 30 40 50 60 70 80 90 100 110 120 130 TJ (°C)
1.30 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 T CASE = 25°C 0.80 0.75 0.70
TCASE = 0°C
TCASE = 125°C
Dropout Voltage vs. Output Current
Reference Voltage vs. Temperature
0.200 0.175
Output Voltage Deviation (%)
2.500
0.150 0.125 0.100 0.075 0.050 0.025 0.000
0 1 2 3 4 Output Current (A) 5 6
Minimum Load Current (mA)
2.175
1.850
TCASE = 125°C
TCASE = 0°C
1.525
1.200 TCASE = 125°C 0.875 TCASE = 25°C
TCASE = 25°C TCASE = 0°C
0.550 1 2 3 4 5 VIN – VOUT (V) 6 7 8 9
Load Regulation vs. Output Current
Minimum Load Current
3
CS5206 -1,-3,-5
Typical Performance Characteristics: continued
70.0 IO = 10mA Ripple Rejection (dB) 65.0 Adjust Pin Current (mA)
100.0 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0
60.0
55.0
50.0
TCASE = 25°C IOUT = 6A (VIN Ð VOUT) = 3V VRIPPLE = 1.6VPP
45.0
10.0
40.0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 Temperature (°C)
0.0
101 102 103 Frequency (Hz) 104 105
Adjust Pin Current vs. Temperature
Ripple Rejection vs. Frequency (Fixed Versions)
100.0 90.0
Ripple Rejection (dB)
80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0
101 102 103 Frequency (Hz) 104 105
TCASE = 25°C IOUT = 6A (VIN Ð VOUT) = 3V VRIPPLE = 1.6VPP CAdj = 25mF
Ripple Rejection vs. Frequency (Adjustable Version)
Applications Information The CS5206 -X family of linear regulators provide fixed or adjustable voltages at currents up to 6A. The regulators are protected against short circuit, and include thermal shutdown and safe area protection (SOA) circuitry. The SOA protection circuitry decreases the maximum available output current as the input-output differential voltage increases. The CS5206 -X has a composite PNP-NPN output transistor and requires an output capacitor for stability. A detailed procedure for selecting this capacitor is included in the Stability Considerations section.
Adjustable Operation
The output voltage is set according to the formula: VOUT = VREF ´ R1 + R2 + IAdj ´ R2 R1 The term IAdj ´ R2 represents the error added by the adjust pin current. R1 is chosen so that the minimum load current is at least 10mA. R1 and R2 should be the same type, e.g. metal film for best tracking over temperature. The adjust pin is bypassed to improve the transient response and ripple rejection of the regulator.
(
)
The adjustable regulator (CS5206 -1) has an output voltage range of 1.25V to 13V. An external resistor divider sets the output voltage as shown in Figure 1. The regulator maintains a fixed 1.25V (typical) reference between the output pin and the adjust pin. A resistor divider network R1 and R2 causes a fixed current to flow to ground. This current creates a voltage across R2 that adds to the 1.25V across R1 and sets the overall output voltage. The adjust pin current (typically 50µA) also flows through R2 and adds a small error that should be taken into account if precise adjustment of VOUT is necessary. 4
VIN C1
VIN
VOUT
VOUT VREF R1 C2
CS5206-1
Adj
IAdj CAdj R2
Figure 1. Resistor divider scheme for the adjustable version.
CS5206-1,-3,-5
Applications Information: continued
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 is 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. However, when the circuit operates at low temperatures, both the value and ESR of the capacitor will vary considerably. The capacitor manufacturers data sheet provides this information. A 22µF tantalum capacitor will work for most applications, but with high current regulators such as the CS5206 -X the transient response and stability improve with higher values of capacitor. The majority of applications for this regulator involve large changes in load current so the output capacitor must supply the instantaneous load current. The ESR of the output capacitor causes an immediate drop in output voltage given by: ÆV = ÆI ´ ESR For microprocessor applications it is customary to use an output capacitor network consisting of several tantalum and ceramic capacitors in parallel. This reduces the overall ESR and reduces the instantaneous output voltage drop under load transient conditions. The output capacitor network should be as close as possible to the load for the best results.
Protection Diodes
IN4002 VIN C1 VIN
(optional) VOUT VOUT
CS5206-X
C2 Gnd
Figure 2b. Protection diode scheme for fixed output regulators.
Output Voltage Sensing
Since the CS5206 -X is a three terminal regulator, it is not possible to provide true remote load sensing. Load regulation is limited by the resistance of the conductors connecting the regulator to the load. For best results the fixed regulators should be connected as shown in Figure 3.
VIN
VIN
VOUT
RC
conductor parasitic resistance
CS5206-X
Gnd
RLOAD
When large external capacitors are used with a linear regulator it is sometimes necessary to add protection diodes. If the input voltage of the regulator gets shorted, the output capacitor will discharge into the output of the regulator. The discharge current depends on the value of the capacitor, the output voltage and the rate at which VIN drops. In the CS5206-X family of linear regulators, the discharge path is through a large junction and protection diodes are not usually needed. If the regulator is used with large values of output capacitance and the input voltage is instantaneously shorted to ground, damage can occur. In this case, a diode connected as shown in Figures 2a and 2b is recommended.
Figure 3. Conductor parasitic resistance can be minimized with the above grounding scheme for fixed output regulators.
For the adjustable regulator, the best load regulation occurs when R1 is connected directly to the output pin of the regulator as shown in Figure 4. If R1 is connected to the load, RC is multiplied by the divider ratio and the effective resistance between the regulator and the load becomes RC ´ R1 + R2 R1
(
)
RC conductor parasitic resistance
RC = conductor parasitic resistance
IN4002 VIN C1 VIN
(optional) VOUT VOUT
VIN
VIN
VOUT
CS5206-1
R1 Adj
RLOAD
CS5206-1
R1 Adj C2
R2
CAdj
R2
Figure 2a. Protection diode scheme for adjustable output regulator.
Figure 4. Grounding scheme for the adjustable output regulator to minimize parasitics.
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CS5206 -1,-3,-5
Applications Information: continued
Calculating Power Dissipation and Heat Sink Requirements
The CS5206 -X series of linear regulators includes thermal shutdown and safe operating area circuitry to protect the device. High power regulators such as these usually operate at high junction temperatures so it is important to calculate the power dissipation and junction temperatures accurately to ensure that an adequate heat sink is used. The case is connected to VOUT on the CS5206 -X, electrical isolation may be required for some applications. Thermal compound should always be used with high current regulators such as these. The thermal characteristics of an IC depend on the following four factors: 1. Maximum Ambient Temperature TA (¡C) 2. Power dissipation PD (Watts) 3. Maximum junction temperature TJ (¡C) 4. Thermal resistance junction to ambient RQJA (C/W) These four are related by the equation TJ = TA + PD ´ RQJA (1)
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 has a thermal resistance. Like series electrical resistances, these resistances are summed to determine RQJA, the total thermal resistance between the junction and the surrounding air. 1. Thermal Resistance of the junction to case, RQJC (¡C/W) 2. Thermal Resistance of the case to Heat Sink, RQCS (¡C/W) 3. Thermal Resistance of the Heat Sink to the ambient air, RQSA (¡C/W) These are connected by the equation: RQJA = RQJC + RQCS + RQSA (3)
The value for RQJA is calculated using equation (3) and the result can be substituted in equation (1). The value for RQJC is normally quoted as a single figure for a given package type based on an average die size. For a high current regulator such as the CS5206 -X the majority of the heat is generated in the power transistor section. The value for RQSA depends on the heat sink type, while RQCS depends on factors such as package type, heat sink interface (is an insulator and thermal grease used?), and the contact area between the heat sink and the package. Once these calculations are complete, the maximum permissible value of RQJA can be calculated and the proper heat sink selected. For further discussion on heat sink selection, see application note ÒThermal Management for Linear Regulators.Ó
The maximum ambient temperature and the power dissipation are determined by the design while the maximum junction temperature and the thermal resistance depend on the manufacturer and the package type. The maximum power dissipation for a regulator is: PD(max)={VIN(max)ÐVOUT(min)}IOUT(max)+VIN(max)IQ where VIN(max) is the maximum input voltage, VOUT(min) is the minimum output voltage, IOUT(max) is the maximum output current, for the application IQ is the maximum quiescent current at IOUT(max). (2)
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CS5206 -1,-3,-5
Package Specification
PACKAGE DIMENSIONS IN mm(INCHES) PACKAGE THERMAL DATA
Thermal Data RQJC RQJA typ typ
3L TO-220 1.6 50
3L D2PAK 1.6 10 - 50*
ûC/W ûC/W
*Depending on thermal properties of substrate. RQJA = RQJC + RQCA
3 Lead TO-220 (T) Straight 3 Lead D2PAK (DP)
10.31 (.406) 10.05 (.396) 1.68 (.066) 1.40 (.055)
10.54 (.415) 9.78 (.385) 2.87 (.113) 2.62 (.103) 3.96 (.156) 3.71 (.146) 4.83 (.190) 4.06 (.160) 1.40 (.055) 1.14 (.045)
1.40 (.055) 1.14 (.045)
8.53 (.336) 8.28 (.326) 15.75 (.620) 14.73 (.580)
14.99 (.590) 14.22 (.560)
6.55 (.258) 5.94 (.234)
2.74(.108) 2.49(.098) 1.40 (.055) 1.14 (.045) 0.91 (.036) 0.66 (.026) 2.79 (.110) 2.29 (.090) .254 (.010) REF
2.54 (.100) REF
1.52 (.060) 1.14 (.045) 14.22 (.560) 13.72 (.540) 1.40 (.055) 1.14 (.045) 6.17 (.243) REF
4.57 (.180) 4.31 (.170)
1.02 (.040) 0.63 (.025)
0.10 (.004) 0.00 (.000)
2.79 (.110) 2.29 (.090) 5.33 (.210) 4.83 (.190)
0.56 (.022) 0.38 (.014) 2.92 (.115) 2.29 (.090)
Ordering Information
Part Number CS5206 -1GT3 CS5206 -1GDP3 CS5206 -1GDPR3 CS5206 -3GT3 CS5206 -3GDP3 CS5206 -3GDPR3 CS5206 -5GT3
Rev. 7/8/97
Description 3 L TO-220 Straight 3 L D2PAK 3 L D2PAK (tape & reel) 6A, 3.3V output 3 L TO-220 Straight 6A, 3.3V output 3 L D2PAK 6A, 3.3V output 3 L D2PAK (tape & reel) 6A, 5V output 3 L TO-220 Straight 7
Type 6A, adj. output 6A, adj. output 6A, adj. output
Cherry Semiconductor Corporation reserves the right to make changes to the specifications without notice. Please contact Cherry Semiconductor Corporation for the latest available information.
© 1999 Cherry Semiconductor Corporation