MP8903 Low Dropout 150mA Linear Regulator

Transcription

1 The Future of Analog IC Technology MP8903 Low Dropout 50mA Linear Regulator DESCRIPTION The MP8903 is a 50mA low-dropout linear regulator that can operate from.7v to 6.5V input. It regulates the output with % accuracy and comes with preset.5v,.85v or 3.3V output. An external resistor divider may be used to adjust the output voltage from.5v to 5V. The MP8903 has thermal protection to guard against harsh operating conditions, and is available in small QFN8 (xmm) and 5-pin TSOT3 packages. FEATURES.7V to 6.5V Input Voltage Range Fixed Output Voltage Options of.5v,.85v or 3.3V Adjustable Output Voltage from.5v to 5V using an External Resistor Divider Low 00mV Dropout at 00mA Output % Accurate Output Voltage Stable With Low-ESR Output Capacitors Thermal Protection Available in Tiny QFN8 (xmm) and TSOT3-5 Packages APPLICATIONS 80. PC Cards Mobile Handset PLL Power Audio Codec Power All MPS parts are lead-free and adhere to the RoHS directive. For MPS green status, please visit MPS website under Products, Quality Assurance page. MPS and The Future of Analog IC Technology are registered trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION.7V to 6.5V MP8903DX-X.X (Pin3) may be connected to (Pin ) directly R R The sum of R and R should not exceed 00k PUT.5V to 5V V DROP (mv) V DROP vs I LOAD I LOAD (ma) MP8903 Rev..

2 MP8903 LOW DROP, 50mA LEAR REGULATOR ORDERG FORMATION Part Number Package Top Marking Free Air Temperature (T A ) MP8903DG.5* R4 MP8903DG.85 QFN8 (xmm) R5 MP8903DG 3.3 R6 MP8903DJ.5 R4 40 C to +85 C MP8903DJ.85 TSOT3-5 R5 MP8903DJ 3.3 R6 * For Tape & Reel, add suffix Z (e.g. MP8903DG.85 Z); For RoHS Compliant Packaging, add suffix LF (e.g. MP8903DG.85 LF Z) PACKAGE REFERCE TOP VIEW TOP VIEW NC 3 MARKG 5 4 QFN8 (xmm) TSOT3-5 ABSOLUTE MAXIMUM RATGS () Supply Voltage V to +7.0V Voltage V to V + 0.3V All Other Pins V to +6V Continuous Power Dissipation (T A = +5 C) () TSOT W QFN8 (xmm)....6w Junction Temperature...50 C Lead Temperature...60 C Storage Temperature C to +50 C Recommended Operating Conditions (3) Input Voltage...7V to 6.5V Output Voltage...5V to 5V Load Current...50mA Maximum Operating Temperature C to +85 C Maximum Junction Temp. (T J )...+5 C Thermal Resistance (4) θ JA θ JC TSOT C/W QFN8 (xmm) C/W Notes: ) Exceeding these ratings may damage the device. ) The maximum allowable power dissipation is a function of the maximum junction temperature T J (MAX), the junction-toambient thermal resistance θ JA, and the ambient temperature T A. The maximum allowable continuous power dissipation at any ambient temperature is calculated by P D (MAX)=(T J (MAX)- T A )/ θ JA. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. 3) The device is not guaranteed to function outside of its operating conditions. 4) Measured on JESD5-7 4-layer board. MP8903 Rev..

3 MP8903 LOW DROP, 50mA LEAR REGULATOR ELECTRICAL CHARACTERISTICS = 5V, T A = +5 C, unless otherwise noted. Parameter Symbol Condition Min Typ Max Units Operating Voltage I = ma V Output Voltage Accuracy I = ma, V =.5V to 5V ±.0 ±.0 % Shutdown Current V = 0V, = 5V 0. μa Regulation Voltage C T A +85 C V = 3V 50 Dropout Voltage (6) I = 50mA V = 4V 5 Line Regulation Load Regulation PSRR V mv I = ma, (7) %/V = (V + 0.5V) to 6.5V I = ma to 50mA, (7) %/ma = V + 0.5V > V +0.5V, C3 =.μf, (5) 50 db (AC) = 00mV, f = khz > V +0.5V, C3 =.μf, (5) (AC) = 00mV, f = MHz 0 db Input High Voltage.5 V Input Low Voltage 0.4 V Input Bias Current V = 0V 0.0 μa Thermal Protection (5) 55 C Thermal Protection Hysteresis (5) 30 C Notes: 5) Parameter is guaranteed by design, not production tested. 6) Dropout Voltage is defined as the input to output differential when the output voltage drops % below its normal value. 7) =.7V for V =.5V to.v MP8903 Rev.. 3

4 MP8903 LOW DROP, 50mA LEAR REGULATOR TYPICAL PERFORMANCE CHARACTERISTICS = 4.5V, V =.85V, C = μf, C = 0.μF, C3 =.μf, T A = +5 C unless otherwise noted I vs I LOAD = 50mA I vs I LOAD = 6.5V = 5.0V I LOAD = ma =.7V (V) I LOAD (ma).87 V vs. 60 V DROP vs I LOAD V (V) I LOAD = ma I LOAD = 50mA V DROP (mv) (V) I LOAD (ma) MP8903 Rev.. 4

5 MP8903 LOW DROP, 50mA LEAR REGULATOR P FUNCTIONS QFN8 (xmm) Pin # TSOT3-5 Pin # Name Description Ground. 3 Enable Input. Drive high to turn on the MP8903; low to turn it off. For automatic startup, connect to. 3, 4 Power Source Input. supplies the internal power to the MP8903 and is the source of the pass transistor. Bypass to with a μf or greater capacitor. 5, 6 5 Regulator Output. is the output of the linear regulator. Bypass to with a μf or greater capacitor. 7 NC No Connect. 8 4 Feedback Input. Connect a resistive voltage divider from to to set the output voltage. The feedback threshold is.v. OPERATION The MP8903 is a low-current, low-dropout linear regulator. The MP8903 uses a PMOS pass element and features internal thermal shutdown. The normally fixed output MP8903 may be converted to an adjustable output device by applying a resistor divider network as shown in Figure. An optional feed-forward capacitor, C BYP, may be added for an improved transient response TERNAL RESISTOR DIVIDER BANDGAP REFERCE C BYP C3 V V Figure Fixed Output Regulator EXTERNAL RESISTOR DIVIDER V R C BYP + -- BANDGAP REFERCE R C V Figure Adjustable Regulator: V = V (+(R/R)) MP8903 Rev.. 5

6 MP8903 LOW DROP, 50mA LEAR REGULATOR APPLICATION FORMATION Setting the Output Voltage The fixed output voltage of the MP8903 is set to.5v,.85v or 3.3V, depending on the internal resistor divider (Figure ). You can also adjust the output voltage by using an external resistor divider (R and R in Figure ). However, the sum of R and R should not exceed 00kΩ in order to minimize the impact of the internal resistor divider. For an accurate output-voltage setting, use 0kΩ (±%) for the low-side resistor R of the voltage divider, while the high-side resistor R can be determined by the equation: V R = R V V Where V is the feedback threshold voltage equal to.v. Example: For.5V Output.5V.V R = = 0.4k Ω.V 0kΩ You can select a standard 0.5kΩ (±%) resistor for R. The following table lists the selected R values for some typical output voltages: Table Adjustable Output Voltage R Values V (V) R (Ω) R (Ω) k k 6.34k.5 0.5k.8 3k 3 4.7k k 4.6k k 0k Input Capacitor Selection For proper operation, place a ceramic capacitor (C) between µf and 0µF of dielectric type X5R or X7R between the input pin and ground. Larger values in this range will help improve line transient response at the drawback of increased size. Output Capacitor Selection For stable operation, use a ceramic capacitor (C3) of type X5R or X7R between µf and 0µF. Larger values in this range will help improve load transient response and reduce noise with the drawback of increased size. Output capacitors of other dielectric types may be used, but are not recommended as their capacitance can deviate greatly from their rated value over temperature. To improve load transient response, add a small ceramic (X5R, X7R or Y5V dielectric) 00nF feed forward capacitor in parallel with R. The feed forward capacitor is not required for stable operation. In Figures 3 and 4, C is added for an improved transient response. MP8903 Rev.. 6

7 MP8903 LOW DROP, 50mA LEAR REGULATOR TYPICAL APPLICATION CIRCUIT.7V to 6.5V 3, 4 5, 6 PUT.85V MP8903DX-.85 C 00nF 8 Figure 3 Typical Application Circuit (Fixed).7V to 6.5V 3, 4 5, 6 PUT V MP8903DX-X.X 8 Figure 4 Typical Application Circuit (Adjustable) MP8903 Rev.. 7

8 MP8903 LOW DROP, 50mA LEAR REGULATOR PCB LAY GUIDE PCB layout is very important to achieve good regulation, ripple rejection, transient response and thermal performance. It is highly recommended to duplicate EVB layout for optimum performance. If change is necessary, please follow these guidelines and take figure 5 for reference. ) Input and output bypass ceramic capacitors are suggested to be put close to the Pin and Pin respectively. ) Ensure all feedback connections are short and direct. Place the feedback resistors and compensation components as close to the chip as possible. 3) Connect, and especially respectively to a large copper area to cool the chip to improve thermal performance and long-term reliability. 3,4 5,6 PUT 5 PUT C R3 MP8903DG 4 8 R R C C3 C R3 3 MP8903DJ 4 R R C C3 R V V R3 8 7 NC C C3 R C C R3 V R R C C3 Top Layer Figure 5 PCB Layout MP8903 Rev.. 8

9 MP8903 LOW DROP, 50mA LEAR REGULATOR PACKAGE FORMATION QFN8 (xmm) P ID MARKG P ID SEE DETAIL A P ID DEX AREA BSC TOP VIEW BOTTOM VIEW 0.0 REF P ID OPTION A R0.0 TYP. P ID OPTION B R0.0 TYP SIDE VIEW DETAIL A.90 NOTE: ) ALL DIMSIONS ARE MILLIMETERS. ) EXPOSED PADDLE SIZE DOES NOT CLUDE MOLD FLASH. 3) LEAD COPLANARITY SHALL BE 0.0 MILLIMETER MAX. 4) DRAWG CONFORMS TO JEDEC MO-9, VARIATION VCCD-3. 5) DRAWG IS NOT TO SCALE RECOMMDED LAND PATTERN MP8903 Rev.. 9

10 MP8903 LOW DROP, 50mA LEAR REGULATOR TSOT TYP 0.95 BSC TYP TYP 3 TOP VIEW RECOMMDED LAND PATTERN BSC MAX SEATG PLANE SEE DETAIL "A" FRONT VIEW SIDE VIEW NOTE: GAUGE PLANE 0.5 BSC 0 o -8 o DETAIL A ) ALL DIMSIONS ARE MILLIMETERS. ) PACKAGE LGTH DOES NOT CLUDE MOLD FLASH, PROTRUSION OR GATE BURR. 3) PACKAGE WIDTH DOES NOT CLUDE TERLEAD FLASH OR PROTRUSION. 4) LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMG) SHALL BE 0.0 MILLIMETERS MAX. 5) DRAWG CONFORMS TO JEDEC MO-93, VARIATION AA. 6) DRAWG IS NOT TO SCALE. NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MP8903 Rev.. 0