19-0516; Rev 1; 9/08 KIT ATION EVALU E L B AVAILA Dual 300mA Pin-Programmable LDO Linear Regulators The MAX8633–MAX8636 offer low-dropout (LDO) voltage and ultra-low-power regulation in a subminiaturized 2mm x 2mm µDFN package. The devices operate from a 2.7V to 5.5V supply and deliver up to 300mA from each output, with a typical dropout voltage of 90mV at 100mA load current. Each device is designed with internal p-channel MOSFET pass transistors to ensure a low-quiescent supply current of 54µA (typical, both LDOs on). Other features include low-noise operation (MAX8634/MAX8636), output current limiting, and thermal shutdown. The MAX8633 features an open-drain, active-low RESET output to monitor OUT2, eliminating external components and adjustments. The MAX8633 asserts a RESET signal (120ms minimum timeout) when VOUT2 drops below 87% of the nominal output voltage. The MAX8634/MAX8636 feature a noise bypass input to the internal reference for low output noise (45µVRMS typ). The MAX8634/MAX8635 provide independent SHDN inputs for disabling the regulators, while the MAX8633/ MAX8636 provide a single SHDN input for disabling both regulators. The MAX8633/MAX8635/MAX8636 have two logic inputs that select one of nine preset output-voltage combinations, eliminating external 1% resistors, as well as inventory burden. The MAX8634 has one logic input to select three output-voltage options. The MAX8633–MAX8636 are available in an 8-pin, 2mm x 2mm µDFN package for minimizing footprint, and an 8-pin, 3mm x 3mm TDFN package for higher power dissipation. The devices are specified over the extended temperature range (-40°C to +85°C). All packages are lead free. Applications Cellular and Cordless Phones Features ♦ Pin-Programmable Output Voltages ♦ 300mA Output Current ♦ Low 90mV Dropout at 100mA Load ♦ Open-Drain, Active-Low RESET (MAX8633) ♦ Low 45µVRMS Output Noise (MAX8634/MAX8636) ♦ Low 54µA Quiescent Supply Current ♦ Low < 1µA Maximum Shutdown Current ♦ Output Current Limit ♦ Thermal Shutdown Ordering Information PINPACKAGE TOP MARK MAX8633ELA+ -40°C to +85°C 8 µDFN 2mm x 2mm AAH MAX8633ETA+ -40°C to +85°C 8 TDFN 3mm x 3mm AOQ MAX8634ELA+ -40°C to +85°C 8 µDFN 2mm x 2mm AAI PART TEMP RANGE +Denotes a lead-free/RoHS-compliant package. Ordering Information continued at end of data sheet. Typical Operating Circuits INPUT 2.7V TO 5.5V IN OUT1 CIN 2.2μF COUT1 2.2μF PDAs and Digital Cameras MAX8633 OUT2 Small LCD Displays Notebook Computers COUT2 2.2μF OUT2 P1 Wireless LAN Cards Handheld Instruments P2 RESET SHDN GND Pin Configurations and Selector Guide appear at end of data sheet. Typical Operating Circuits continued at end of data sheet. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX8633–MAX8636 General Description MAX8633–MAX8636 Dual 300mA Pin-Programmable LDO Linear Regulators ABSOLUTE MAXIMUM RATINGS (All voltages refer to GND, unless otherwise noted.) IN ...........................................................................-0.3V to +6.0V SHDN, SHDN1, SHDN2, RESET, P, P1, P2, BP, OUT1, OUT2 .....................-0.3V to (VIN + 0.3V) Continuous Output Short-Circuit Duration..................Continuous Continuous Power Dissipation (TA = +70°C) 8-Pin µDFN 2mm x 2mm (derate 4.8mW/°C above +70°C) .................................380mW 8-Pin TDFN 3mm x 3mm (derate 23.8mW/°C above +70°C) .............................1904mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VIN = 3.7V, SHDN = SHDN1 = SHDN2 = IN, P = P1 = P2 = GND, CIN = 2.2µF, COUT1 = 2.2µF, COUT2 = 2.2µF, CBP = 0.01µF, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Input Voltage Input Undervoltage Lockout Ground Current Shutdown Supply Current SYMBOL CONDITIONS MAX UNITS 5.5 V 2.25 2.35 V IOUT_ = 0mA 54 75 IOUT_ = 100mA 60 IOUT_ = 10mA, dropout (Note 2) 60 VIN VUVLO IQ IOFF MIN TYP 2.7 VIN rising; hysteresis = 95mV (typ) SHDN_ = GND 2.15 TA = +25°C 0.005 TA = +85°C 0.01 µA 1 µA OUT1, OUT2 IOUT_ = 70mA; TA = +25°C Output Voltage Accuracy (for Any Output Voltage) Current Limit Drop-Out Voltage ILIM VIN - VOUT 2 +0.7 -1 +1 IOUT_ = 0.1mA to 300mA; VIN = (VOUT_ + 0.5V) to 5.5V -1.8 +1.7 OUT_ = 0V 400 VOUT_ = 2.8V (MAX8633); VOUT_ = 2.85V (MAX8634/MAX8635/MAX8636); IOUT_ = 100mA (Note 2) f = 10Hz to 100kHz; IOUT_ = 10mA Output Noise Output AC PowerSupply Rejection Ratio -0.7 IOUT_ = 70mA PSRR % 500 600 mA 90 200 mV MAX8633 MAX8635 450 MAX8634 MAX8636 45 f < 1kHz 60 f < 10kHz 55 µVRMS IOUT_ = 30mA dB _______________________________________________________________________________________ Dual 300mA Pin-Programmable LDO Linear Regulators (VIN = 3.7V, SHDN = SHDN1 = SHDN2 = IN, P = P1 = P2 = GND, CIN = 2.2µF, COUT1 = 2.2µF, COUT2 = 2.2µF, CBP = 0.01µF, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SHUTDOWN INPUTS (SHDN, SHDN1, AND SHDN2) Input Voltage High VIH VIN = 2.7V to 5.5V Input Voltage Low VIL VIN = 2.7V to 5.5V Input Bias Current ISHDN_ VIN = 2.7V to 5.5V; VSHDN_ = GND or IN 1.5 0.5 TA = +25°C 0.1 TA = +85°C 1 From SHDN = high to 87% of VOUT_; IOUT_ = 70mA Turn-On Delay 1000 90 V nA µs TRI-LEVEL INPUTS (P, P1, P2) Termination Resistance to IN or GND for Setting High, Open, and Low States IN = 2.7 to 5.5V Input Load Capacitance for Open State Design guide only For high or low state 1 kΩ For open state 100 50 pF 90 % RESET RESET High Threshold Percent of nominal OUT2; OUT2 rising RESET Threshold Hysteresis Percent of nominal OUT2; OUT2 falling 4.5 IRESET = 20µA; VIN = 1.0V 10 100 IRESET = 500µA; VIN = 3.7V 5 100 TA = +25°C 0.1 300 TA = +85°C 1 RESET Output Voltage Low RESET Output High Leakage Current ILEAK RESET Delay tRP VRESET = VIN = 5.5V From OUT2 rising to RESET rising 84 120 87 150 % 180 mV nA ms THERMAL PROTECTION Thermal-Shutdown Threshold TSHDN +165 °C Thermal-Shutdown Hysteresis ΔTSHDN 15 °C Note 1: All units are 100% tested at TA = +25°C. Limits over the operating temperature range are guaranteed by design. Note 2: The dropout voltage is defined as VIN - VOUT_ when VOUT_ drops by 100mV from VOUT_ when measured at VIN = +3.7V. Note 3: Connect P_ to IN or GND through a resistor less than 1kΩ. _______________________________________________________________________________________ 3 MAX8633–MAX8636 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VIN = 3.8V, P = P1 = P2 = GND, IOUT1, 2 = 70mA, COUT1 = 2.2µF, COUT2 = 2.2µF, CBP = 0.01µF, CIN = 2.2µF, and TA = +25°C, unless otherwise noted.) 50 IOUT1 = IOUT2 = 0mA 40 30 20 65 60 IOUT1 = IOUT2 = 70mA 65 SUPPLY CURRENT (μA) SUPPLY CURRENT (μA) 60 70 MAX8633 toc02 IOUT1 = IOUT2 = 70mA SUPPLY CURRENT (μA) 70 MAX8633 toc01 70 SUPPLY CURRENT vs. TEMPERATURE (MAX8633ELA+) SUPPLY CURRENT vs. LOAD CURRENT (MAX8635ELA+) MAX8633 toc03 SUPPLY CURRENT vs. SUPPLY VOLTAGE (MAX8633ELA+) 60 55 IOUT1 = IOUT2 = 0mA 50 55 45 10 P1 = P2 = IN 1 2 3 4 6 5 50 0 100 150 200 10 35 85 60 DROPOUT VOLTAGE vs. LOAD CURRENT (MAX8633ELA+) DROPOUT VOLTAGE vs. OUT1 VOLTAGE (MAX8633ELA+) OUTPUT VOLTAGE ACCURACY vs. TEMPERATURE (MAX8633ELA+) 0.10 70 60 50 1.5 OUT1 P1 = P2 = IN OUT1 0 50 100 150 200 250 2.65 2.70 2.75 2.80 2.85 OUT1 VOLTAGE (V) LOAD CURRENT (mA) PSRR vs. FREQUENCY (MAX8636ELA+) 70 PSRR (dB) 40 30 20 10 35 60 85 OUTPUT SPECTRAL NOISE DENSITY vs. FREQUENCY (MAX8636ELA+) 40 30 20 ROUT1 = 100Ω P1 = IN P2 = GND -15 TEMPERATURE (°C) 50 0.1 -1.0 -40 10,000 NOISE DENSITY (nV/ Hz) 60 50 0.01 OUT1 -0.5 2.90 2.95 MAX8633 toc08 60 0 CHANNEL-TO-CHANNEL ISOLATION vs. FREQUENCY (MAX8636ELA+) MAX8633 toc07 70 0.5 -2.0 2.60 300 1.0 -1.5 40 0 MAX8633 toc06 2.0 OUT1 VOLTAGE ACCURACY (%) DROPOUT VOLTAGE (mV) 0.15 MAX8633 toc05 MAX8633 toc04 80 0.05 OUT1 P1 = IN P2 = GND 1000 100 10 ROUT1 = 100Ω 10 0 1 FREQUENCY (kHz) 4 -15 TEMPERATURE (°C) 0.20 0 -40 300 LOAD CURRENT (mA) 0.25 10 250 SUPPLY VOLTAGE (V) 0.30 DROPOUT VOLTAGE (V) 40 50 0 MAX8633 toc09 0 PSRR (dB) MAX8633–MAX8636 Dual 300mA Pin-Programmable LDO Linear Regulators 10 100 0.01 0.1 1 FREQUENCY (kHz) 10 100 0.01 0.1 1 10 FREQUENCY (kHz) _______________________________________________________________________________________ 100 1000 Dual 300mA Pin-Programmable LDO Linear Regulators OUTPUT NOISE DC TO 100kHz (MAX8636ELA+) LINE TRANSIENT RESPONSE (MAX8633ELA+) MAX8633 toc10 MAX8633 toc11 4.8V VIN 1V/div 3.8V 0 50μV/div 10mV/div AC VOUT1 MAX8633 IOUT1 = 70mA 1ms/div 40μs/div LOAD TRANSIENT (MAX8633ELA+ OUT1 ILOAD = 1mA TO 70mA) LOAD TRANSIENT NEAR DROPOUT (VIN = VOUT + 0.1V, MAX8633ELA+ OUT1) MAX8633 toc12 MAX8633 toc13 70mA IOUT1 70mA 100mA/div 1mA IOUT1 100mA/div 1mA 0 0 20mV/div AC VOUT1 20mV/div AC VOUT1 MAX8633 VIN = 3.8V MAX8633 VIN = VOUT1 + 0.1V 40μs/div 40μs/div RESET TIMING (MAX8633ELA+) OUT1 AND OUT2 TURN-ON SEQUENCE (MAX8633ELA+) MAX8633 toc14 MAX8633 toc15 5V/div SHDN 0 SHDN OUT1 2V/div OUT1 0 OUT2 2V/div 0 MAX8633 40ms/div SHDN1 2V/div 0 0 2V/div 0 MAX8633 toc16 MAX8633 P1 = P2 = GND IOUT1 = IOUT2 = 70mA 2V/div RESET EXITING SHUTDOWN (MAX8634ELA+) 40μs/div 2V/div 0 2V/div OUT1 SHDN2 OUT2 2V/div 0 2V/div MAX8634 P = IN ROUT1 = ROUT2 = 100Ω 40μs/div _______________________________________________________________________________________ 5 MAX8633–MAX8636 Typical Operating Characteristics (continued) (VIN = 3.8V, P = P1 = P2 = GND, IOUT1, 2 = 70mA, COUT1 = 2.2µF, COUT2 = 2.2µF, CBP = 0.01µF, CIN = 2.2µF, and TA = +25°C, unless otherwise noted.) Dual 300mA Pin-Programmable LDO Linear Regulators MAX8633–MAX8636 Pin Description PIN MAX8633 MAX8634 1 1 MAX8635 1 MAX8636 1 NAME IN FUNCTION Regulator Input. Supply voltage from 2.7V to 5.5V. Bypass IN with a ceramic capacitor of at least 2.2µF to GND (see the Capacitor Selection and Regulator Stability section). 2 — — 2 SHDN Shutdown Input, Active Low. Drive SHDN logic low to shut down both regulators. Connect SHDN to IN or drive logic high for normal operation (see the Power-On Sequence (MAX8633/Max8636 Only) section). — 2 2 — SHDN1 LDO1 Shutdown Input, Active Low. Drive SHDN1 logic low to shut down OUT1. Connect SHDN1 to IN or drive logic high for normal operation. — 3 5 — SHDN2 LDO2 Shutdown Input, Active Low. Drive SHDN2 logic low to shut down OUT2. Connect SHDN2 to IN or drive logic high for normal operation. 3 — 3 3 P2 Programming Input 2. The state of P1 and P2 selects one of nine output-voltage options (see Tables 1, 3). 4 — 4 4 P1 Programming Input 1. The state of P1 and P2 selects one of nine output-voltage options (see Tables 1, 3). — 4 —— — P Programming Input. The state of P selects one of three output-voltage options for the MAX8634 (see Table 2). Reset Output, Active Low, Open Drain. RESET goes high impedance 120ms (min) after VOUT2 rises above 87% of the nominal output voltage. RESET is forced logic low when VOUT2 is below 82.5% of the nominal output voltage. Connect RESET to OUT1, OUT2, or another voltage of VIN or lower with a pullup resistor. 5 — — — RESET — 5 — 5 BP 6 6 6 6 GND Ground OUT2 Regulator 2 Output. Guaranteed 300mA output current (see the Calculating Maximum Output Power section). Bypass OUT2 with a ceramic capacitor of at least 2.2µF to GND (see the Capacitor Selection and Regulator Stability section). 7 7 7 7 Reference Noise Bypass. Bypass BP to GND with a 0.01µF ceramic capacitor to reduce output noise. 8 8 8 8 OUT1 Regulator 1 Output. Guaranteed 300mA output current (see the Calculating Maximum Output Power section). Bypass OUT1 with a ceramic capacitor of at least 2.2µF to GND (see the Capacitor Selection and Regulator Stability section). EP* EP* EP* EP* EP Exposed Paddle. Solder the exposed paddle to a large pad or circuit-board ground plane to increase thermal dissipation. *TDFN package only. 6 _______________________________________________________________________________________ Dual 300mA Pin-Programmable LDO Linear Regulators IN * SHDN ** SHDN1 SHDN2 ** UVLO/ SHUTDOWN AND POWER-ON CONTROL MOS DRIVER WITH ILIMIT ERROR AMP THERMAL SENSOR OUT1 1.50V REF OUTPUTVOLTAGE CONTROL P1 P2 P RESET (MAX8633 ONLY) 87% REF (MAX8634 ONLY) GND DELAY BP*** IN OUT2 LD02 *MAX8633, MAX8636 ONLY **MAX8634, MAX8635 ONLY ***MAX8634, MAX8636 ONLY _______________________________________________________________________________________ 7 MAX8633–MAX8636 Functional Diagram MAX8633–MAX8636 Dual 300mA Pin-Programmable LDO Linear Regulators Detailed Description The MAX8633–MAX8636 are low-power, low-quiescent current, low-dropout linear regulators designed primarily for battery-powered applications. Pin-programmable inputs allow easy configuration of OUT1 and OUT2 voltages without external 1% resistors. The devices can supply up to 300mA from each output, provided they do not exceed the maximum package power dissipation. The MAX8633–MAX8636 regulate OUT1 and OUT2 by using simple control loops incorporating internal 1.50V reference, error amplifiers, p-channel pass transistors, and internal feedback voltage-dividers. Reset circuitry ensures controlled startup and provides undervoltage lockout. The MAX8633–MAX8636 determine output voltages at OUT1 and OUT2 based on the state of P1 and P2 (P for MAX8634) at power-on. RESET (MAX8633) The MAX8633 features an integrated reset circuit. RESET is logic-low on power-up and goes high impedance 150ms after OUT2 reaches 87% of its nominal regulation voltage. During power-down or undervoltage conditions, RESET is driven low when OUT2 falls below 82.5% of its nominal regulation voltage. Output Programming Inputs (P1, P2, P) Output voltages for OUT1 and OUT2 are determined at power-up by the state of P1 and P2. Programming inputs P1 and P2 eliminate external 1% feedback resistors while providing nine preset output-voltage options (see Table 1 for the MAX8633; see Table 3 for the MAX8635/MAX8636). The MAX8634 provides three preset output-voltage options with one programming input (see Table 2). The MAX8633–MAX8636 configure output voltages at OUT1 and OUT2 based on the state of P1 and P2 (P for Table 1. Output-Voltage Programming (MAX8633) 8 MAX8634) at power-on. Subsequent changes to P, or P1 and P2 do not change the output voltages unless the supply power is cycled, or all SHDN inputs are simultaneously driven low to shut down the device. Power-On Sequence (MAX8633/MAX8636 Only) The MAX8633/MAX8636 provide a single shutdown input (SHDN) to disable OUT1 and OUT2. During power-on, inrush current is limited by a built-in startup sequence. At power-on, OUT1 is disabled until OUT2 reaches 87% of its regulation voltage, then OUT1 is enabled. If SHDN is connected to IN and the input voltage drops below the undervoltage-lockout (UVLO) threshold, both LDOs are disabled. The LDOs will not power on again until both of the following conditions are satisfied: 1) The input voltage is raised above the UVLO threshold 2.25V (typ). 2) OUT2 is discharged below 1.2V (typ). Internal p-Channel Pass Transistor The MAX8633–MAX8636 feature 0.9Ω p-channel MOSFET pass transistors; p-channel MOSFETs provide several advantages over similar designs using pnp pass transistors, resulting in higher efficiency and longer battery life. MOSFET pass transistors do not require base drive current of pnps, reducing quiescent current Table 2. Output-Voltage Programming (MAX8634) P OUT1 (V) OUT2 (V) Open 2.85 2.85 GND 3.00 2.85 IN 2.60 2.60 Table 3. Output-Voltage Programming (MAX8635/MAX8636) (OUT2) (V) P1 P2 OUT1 (V) 2.80 1.50 Open Open 2.80 1.50 2.90 1.50 Open GND 2.90 1.50 3.00 1.50 Open IN 3.00 1.50 Open 3.00 1.60 GND Open 2.60 1.80 GND 2.80 1.80 GND GND 2.80 1.80 GND IN 2.60 1.85 GND IN 3.00 2.50 IN Open 2.90 1.85 IN Open 3.00 2.80 IN GND 2.80 2.60 IN GND 2.85 2.85 IN IN 3.00 2.80 IN IN 3.00 3.00 P1 P2 Open Open Open GND Open IN GND GND OUT1 (V) _______________________________________________________________________________________ OUT2 (V) Dual 300mA Pin-Programmable LDO Linear Regulators Current Limit The MAX8633–MAX8636 provide independent current limiting for OUT1 and OUT2. Output current is limited to 500mA (typ) and 400mA (min) for each regulator. Shutdown (SHDN1, SHDN2, SHDN) The MAX8634/MAX8635 have independent shutdown control inputs (SHDN1 and SHDN2) and the MAX8633/ MAX8636 have one shutdown control input (SHDN) for both outputs. Drive SHDN1 low to shut down OUT1. Drive SHND2 low to shut down OUT2. Drive both SHDN1 and SHDN2 low to shut down the entire device, reducing supply current to 1µA max. For the MAX8634, drive SHDN low to shut down the entire device. Connect SHDN1, SHDN2, or SHDN to a logic-high or IN to permanently enable the corresponding LDO(s). Thermal-Overload Protection Thermal-shutdown circuitry protects the MAX8633– MAX8636 from damage due to excessive junction temperature. The shutdown circuit disables OUT1 and OUT2 when the junction temperature (TJ) exceeds +165°C. Both regulators are reenabled when TJ falls by 15°C. Low-Noise Operation (MAX8634/MAX8636) An external 0.01µF bypass capacitor at BP in conjunction with an internal resistor creates a lowpass filter. The MAX8634/MAX8636 exhibit less than 45µVRMS of output voltage noise with CBP = 0.01µF and COUT = 2.2µF. These values are shown in the Output Noise Spectral Density graph in the Typical Operating Characteristics section. If output noise is not critical, omit the BP capacitor to reduce total solution size and cost. Applications Information Capacitor Selection and Regulator Stability ture range. Output capacitors can be reduced to 1µF for load currents less than 150mA. The MAX8633– MAX8636 are optimized for ceramic capacitors and require low equivalent-series resistance (ESR) to achieve the stated specifications for low-output noise and power-supply rejection. To ensure proper operation over the specified temperature range, dielectrics such as X7R or X5R are recommended. If Z5U or Y5V dielectrics are used, it may be necessary to increase the value of the output capacitors to ensure stability at temperatures below -10°C. Tantalum capacitors are not recommended due to their higher ESR. For loads up to 300mA, or for improved load-transient response, 2.2µF or larger output capacitors can be used. PSRR and Operation from Sources Other than Batteries The MAX8633–MAX8636 deliver low-dropout voltages and low-quiescent currents in battery-powered systems. When operating from sources other than batteries, improved supply-noise rejection and transient response can be achieved by increasing the values of the input and output capacitors and through passive filtering techniques. Power-supply rejection is 60dB at frequencies below 1kHz (see the Power-Supply Rejection Ratio vs. Frequency in the Typical Operating Characteristics). P1 and P2 (P for MAX8634) External Termination The pin-programmable inputs (P1 and P2 for MAX8633/MAX8635/MAX8636, P for MAX8634) should be connected to IN, GND, or left open. If P_ inputs are left open, ensure the external capacitance is less than 50pF. If P_ inputs are set high or low, ensure the resistance to IN or GND is less than 1kΩ. The MAX8633– MAX8636 configure output voltages at OUT1 and OUT2 based on the state of P1 and P2 (P for MAX8634) at power-on. Subsequent changes to P, or P1 and P2 do not change the output voltages unless the supply power is cycled, or all SHDN inputs are simultaneously driven low to shut down the device. Load-Transient Considerations The MAX8633–MAX8636 load-transient response graphs (see Typical Operating Characteristics) show two components of the output response: a DC step in the output voltage due to the change in load current, and the transient response. Increase the value and decrease the ESR of the output capacitor to attenuate transient spikes. Use a ceramic input capacitor of at least 2.2µF and a ceramic output capacitor of at least 2.2µF for each output to ensure stable operation over the entire tempera_______________________________________________________________________________________ 9 MAX8633–MAX8636 considerably. Under heavy loads, pnp base-drive current becomes large, further reducing efficiency; pnpbased regulators also require considerable current in dropout when the pass transistor saturates. The MAX8633–MAX8636 do not suffer from these problems. With both outputs active, the devices consume only 54µA of quiescent current at no load, and 60µA with 100mA load current for each output (see Typical Operating Characteristics). A pnp-based regulator has a high dropout voltage that is independent of the load. The dropout voltage of a p-channel MOSFET is proportional to load current providing for low-dropout voltage at heavy loads and extremely low dropout at lighter loads. MAX8633–MAX8636 Dual 300mA Pin-Programmable LDO Linear Regulators Input-Output Voltage (Dropout Voltage) PC Board Layout Guidelines A regulator’s minimum input-output voltage differential (or dropout voltage) determines the lowest usable supply voltage. In battery-powered systems, this determines the useful end-of-life battery voltage. Because the MAX8633–MAX8636 use a p-channel MOSFET pass transistor, dropout voltage is a function of drainto-source on-resistance (RDS(ON)) multiplied by the load current (see Typical Operating Characteristics). Follow these guidelines for good PC board layout: • Keep the input and output traces short and wide if possible, especially at the ground terminals. Calculating Maximum Output Power The maximum output power of the MAX8633–MAX8636 is limited by the maximum power dissipation of the package. By calculating the power dissipation of the device as a function of the input voltage, output voltages, and output currents, the worst-case power dissipation can be obtained. The worst-case power dissipation should not exceed the package’s maximum power rating: where: PD = VIN(MAX) – VOUT1 x I OUT1 + ( • Use thick copper PC boards to enhance thermal performance. Connect the exposed paddle of the TDFN package to the ground plane or a large copper pad. • Place output, input, and bypass capacitors as close as possible to the IC. • Ensure the noise bypass capacitor and associated PC board traces are routed away from noise sources to ensure low-output voltage noise. An evaluation kit (MAX8633EVKIT) is available for a layout example to speed designs. Selector Guide ) (VIN(MAX) − VOUT2 ) x IOUT2 PART OUTPUT VOLTAGE OPTIONS SHDN INPUTS VIN(MAX) = Maximum input voltage MAX8633 9 VOUT1 = Output voltage of OUT1 VOUT2 = Output voltage of OUT2 IOUT1 = Maximum output current of OUT1 IOUT2 = Maximum output current of OUT2 PD must be less than PDMAX, the maximum power dissipation of the package. If PD is greater than PDMAX, consider using the 8-pin TDFN package. P DMAX = 380mW for the 8-pin µDFN. Derate by 4.8mW/°C above +70°C. P DMAX = 1904mW for the 8-pin TDFN. Derate by 23.8mW/°C above +70°C. MAX8634 3 MAX8635 MAX8636 LOW NOISE RESET 1 — YES 2 YES — 9 2 — — 9 1 YES — Ordering Information (continued) PINPACKAGE TOP MARK MAX8634ETA+ -40°C to +85°C 8 TDFN 3mm x 3mm AOR MAX8635ELA+ -40°C to +85°C 8 µDFN 2mm x 2mm AAJ MAX8635ETA+ -40°C to +85°C 8 TDFN 3mm x 3mm AOS MAX8636ELA+ -40°C to +85°C 8 µDFN 2mm x 2mm AAK MAX8636ETA+ -40°C to +85°C 8 TDFN 3mm x 3mm AOT PART TEMP RANGE +Denotes a lead-free/RoHS-compliant package. 10 ______________________________________________________________________________________ Dual 300mA Pin-Programmable LDO Linear Regulators TOP VIEW OUT1 OUT2 GND RESET 8 7 6 5 OUT1 OUT2 GND 8 MAX8633 7 6 BP 5 MAX8634 *EP *EP 1 2 3 4 1 IN SHDN P2 P1 IN 2 3 4 SHDN1 SHDN2 P 2mm x 2mm μDFN 3mm x 3mm TDFN 2mm x 2mm μDFN 3mm x 3mm TDFN OUT1 OUT2 GND SHDN2 OUT1 OUT2 GND 8 7 6 5 8 MAX8635 7 6 BP 5 MAX8636 *EP *EP 1 2 3 4 1 2 3 4 IN SHDN1 P2 P1 IN SHDN P2 P1 2mm x 2mm μDFN 3mm x 3mm TDFN 2mm x 2mm μDFN 3mm x 3mm TDFN *EP = EXPOSED PADDLE. CONNECT EXPOSED PADDLE TO GND (TDFN ONLY). Chip Information PROCESS: BiCMOS CONNECT EXPOSED PADDLE TO GND. ______________________________________________________________________________________ 11 MAX8633–MAX8636 Pin Configurations Dual 300mA Pin-Programmable LDO Linear Regulators MAX8633–MAX8636 Typical Operating Circuits (continued) INPUT 2.7V TO 5.5V IN OUT1 CIN 2.2μF COUT1 2.2μF MAX8634 OUT2 COUT2 2.2μF P SHDN1 BP CBP 0.01μF SHDN2 GND INPUT 2.7V TO 5.5V INPUT 2.7V TO 5.5V IN IN OUT1 CIN 2.2μF COUT1 2.2μF P1 COUT1 2.2μF MAX8635 OUT2 MAX8636 OUT2 COUT2 2.2μF P2 OUT1 CIN 2.2μF COUT2 2.2μF P1 SHDN1 P2 SHDN2 SHDN GND BP CBP 0.01μF GND Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. 12 PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 8 TDFN T833-2 21-0137 8 µDFN L822-1 21-0164 ______________________________________________________________________________________ Dual 300mA Pin-Programmable LDO Linear Regulators PAGES CHANGED REVISION NUMBER REVISION DATE 0 4/06 Initial release — 1 9/08 Added LDO SHDN restart conditions 8 DESCRIPTION Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 13 © 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. MAX8633–MAX8636 Revision History