CS8321 CHERRY | Alldatasheet
Document overview
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Technical content
Features
+ - Current Limit Sense VOUTSense* Bandgap Reference Current Source (Circuit Bias) QP QN R *Note: Lead shorted to VOUT in 3 pin applications n 5V ±2% Output n Low 140µA (typ) Quiescent Current n 150mA Output Current Capability n Fault Protection -15V Reverse Voltage Output Current Limit n Low Reverse Current (Output to Input) Package Options CS8321 Micropower 5V , 150mA Low Dropout Linear Regulator CS8321
Description
The CS8321 is a precision 5V micropower voltage regulator with very low quiescent current (140µA typ at 1mA load). The 5V output is accurate within ±2% and supplies 150mA of load current with a typi- cal dropout voltage of only 300mV. This combination of low quiescent current and outstanding regulator performance makes the CS8321 ideal for any battery operated equipment. The regulator is protected against reverse battery and short circuit conditions. The device can with- stand 45V load dump transients making it suitable for use in auto- motive environments. Block Diagram 3L D2PAK 1. VIN 2. Gnd 3. VOUT Other Packages: 16L SO, 16L PDIP, 8L SO, 8L PDIP, (consult factory) 3L TO-220 1. VIN 2. Gnd 3. VOUT Lead Temperature Soldering Absolute Maximum Ratings A Company ¨ Rev. 11/25/96 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
Electrical Characteristics: 6V < VIN < 26V, IOUT=1mA, -40¡C ² TA ² 125¡C, -40¡C ² TJ ² 150¡C unless otherwise specified. transistor with antisaturation control, and current limit. to rise as QPÕs output current charges the output capacitor. PNP transistor, as shown in Figure 1. Figure 1. The parasitic PNP transistor which is part of the pass transis-
11 V IN Input Voltage
2 2 Gnd Ground. All Gnd leads must be connected to Ground.
Circuit Description and Application Notes: continued The maximum power dissipation for a single output regu- lator (Figure 3) is: PD(max)=(VIN(max)ÐVOUT(min))IOUT(max)+VIN(max)IQ (1) where: VIN(max) is the maximum input voltage, VOUT(min) is the minimum output voltage, IOUT(max) is the maximum output current for the applica- tion, and 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 R QJA'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. Figure 4: Single output regulator with key performance parameters labeled. 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 R QJA: 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. Heatsinks VIN CS8321 VOUT IOUT IIN IQ 150¡C - TA PD Calculating Power Dissipation in a Single Output Linear Regulator
Thermal Data TO-220 D 2PAK RQJC typ 3.5 1.0* ûC/W RQJA typ 50 10 - 50** ûC/W *Depending on die area **Depending on thermal properties of substrate.RQJA = RQJC + RQCA Package Specification PACKAGE DIMENSIONS IN mm(INCHES) PACKAGE THERMAL DATA CS8321
3 Lead TO-220 (T) Straight
5.33 (.210) 4.83 (.190) 2.79 (.110) 2.29 (.090) 1.02 (.040) 0.63 (.025) 0.56 (.022) 0.38 (.014) 1.40 (.055) 1.14 (.045) 4.83 (.190) 4.06 (.160) 6.17 (.243) REF 1.14 (.045) 1.52 (.060) 1.14 (.045) 1.40 (.055) 2.87 (.113) 5.94 (.234) 14.22 (.560) 13.72 (.540) 2.92 (.115) 2.29 (.090) 9.78 (.385) 10.54 (.415) 3.71 (.146) 3.96 (.156) 14.99 (.590) 14.22 (.560)
6 © 1999 Cherry Semiconductor CorporationRev. 11/25/96 Cherry Semiconductor Corporation reserves the right to make changes to the specifications without notice. Please contact Cherry Semiconductor Corporation for the latest available information. Part Number Description CS8321YT3 3L TO-220 Straight CS8321YDP3 3L D 2PAK CS8321YDPR3 3L D 2PAK (tape & reel) Package Specification: continued
Ordering Information
3 Lead D2PAK (DP)
2.54 (.100) REF 10.31 (.406) 10.05 (.396) 8.53 (.336) 8.28 (.326) 0.91 (.036) 0.66 (.026) 1.40 (.055) 1.14 (.045) 4.57 (.180) 4.31 (.170) 1.68 (.066) 1.40 (.055) 2.74(.108) 2.49(.098) 1.40 (.055) 1.14 (.045) 0.10 (.004) 0.00 (.000) .254 (.010) REF 15.75 (.620) 14.73 (.580) 2.79 (.110) 2.29 (.090)