19-2075; Rev 0; 7/01 Integrated Cellular RF-Section Power-Management IC The first LDO is intended to power the transmitter, receiver, and synthesizer. The second LDO is intended to power the TCXO, and high-power voltage-controlled oscillators (VCOs). The third LDO is intended to power the UHF offset VCO. Each LDO has its own individual enable (ON/OFF) control to maximize design flexibility. The reference is powered on if any of the enable inputs (EN1, EN2, EN3) are logic high. The high-accuracy output voltage of each LDO is preset at an internally trimmed voltage (1.8V to 3.3V in 50mV increments). Each LDO is capable of supplying 100mA with a low 50mV dropout and is optimized for low noise and high crosstalk-isolation. Designed with internal P-channel MOSFET pass transistors, the MAX8890’s low 180µA operating supply current is independent of load. Other features include short-circuit and thermal overload protection. The MAX8890 is available in a compact, high-power, 12-pin 4mm ✕ 4mm QFN package with a metal pad on the underside. Applications Cellular Handsets Single-Cell Li+ Systems 3-Cell NiMH, NiCD, or Alkaline Systems Personal Digital Assistants (PDAs) Standard Preset Output Voltage Suffixes SUFFIX OUTPUT VOLTAGE (V) SUFFIX OUTPUT VOLTAGE (V) A 3.30 H 2.75 B 3.00 J 2.70 D 2.90 K 2.50 F 2.85 L 2.00 G 2.80 M 1.80 *Nonstandard output voltages between 1.80V and 3.30V are available in 50mV increments. Features ♦ Three 100mA Low-Dropout Linear Regulators ♦ Low 50mV Dropout Voltage at 100mA ♦ ±1% Output Voltage Accuracy Over Temperature ♦ Preset 1.8V to 3.3V Output Voltages (in 50mV Increments) ♦ Low 45µVRMS Output Voltage Noise ♦ Low 180µA Operating Supply Current ♦ 2.5V to 5.5V Input Voltage Range ♦ 67dB PSRR ♦ 10µVp-p Channel-to-Channel Crosstalk ♦ Short-Circuit Protection ♦ Thermal Overload Protection ♦ 0.01µA Shutdown Current ♦ Tiny 12-Pin 4mm x 4mm QFN Package Ordering Information PART TEMP. RANGE PIN-PACKAGE MAX8890EGCxyz* -40°C to +85°C 12 (4 x 4) QFN *Each preset output voltage of these devices is factory trimmed to one of ten voltages. Replace “xyz” with the letters corresponding to the desired output voltages (see Standard Preset Output Voltage Suffixes table), where the three letter suffix corresponds to the following output voltages: “x” = VOUT1, “y” = VOUT2, and “z” = VOUT3. Note: There are five standard versions available (see Standard Versions table). Sample stock is generally held on standard versions only. Standard versions have an order increment requirement of 2500 pieces. Nonstandard versions have an order increment requirement of 10,000 pieces. Contact the factory for availability of nonstandard versions. Typical Operating Circuit INPUT IN1 OUT1 OUTPUT #1 IN2 OUT2 OUTPUT #2 IN3 OUT3 OUTPUT #3 EN1 BP MAX8890 ON OFF EN2 EN3 GND Standard Versions table and Pin Configuration appear 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 MAX8890 General Description The MAX8890 is a power-management IC intended for cellular handsets using a single lithium-ion (Li+) cell battery with input voltages from +2.5V to +5.5V. The IC contains three identical, low-noise, low-dropout (LDO) linear regulators to provide all of the supply voltage requirements for the RF portion of the handset. MAX8890 Integrated Cellular RF-Section Power-Management IC ABSOLUTE MAXIMUM RATINGS IN_, EN_ to GND.......................................................-0.3V to +6V OUT_, BP to GND ......................................-0.3V to (VIN_ + 0.3V) Output Short-Circuit Protection (Note A) .......................indefinite Continuous Power Dissipation (TA = +70°C) 12-Pin 4 x 4 QFN (derate 16.9mW/°C above +70°C) .......1349mW 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 Note A: As long as the maximum continuous power dissipation rating is not exceeded, the output may be shorted indefinitely. 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_ = 3.6V, EN_ = IN_, CIN = 6.8µF, COUT_ = 2.2µF, CBP = 0.01µF, all ceramic capacitors TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 5.5 V 2.45 V GENERAL Input Voltage Input Undervoltage Lockout Threshold VIN_ VUVLO 2.5 Rising and falling edge 2.10 Input Undervoltage Hysteresis 2.25 45 mV SUPPLY CURRENT Quiescent Supply Current IQ Shutdown Supply Current IOUT_ = 0 180 330 µA EN_ = OUT_ = GND 0.01 10 µA LINEAR REGULATORS Output Voltage Accuracy Current Limit Output Pulldown Resistance Dropout Voltage (Note 1) VOUT_ ILIM ROUT_ VIN_ VOUT_ VIN_ = 0.5V + the highest of (VOUT1, VOUT2, or VOUT3), IOUT_ = 1mA to 100mA TA = +85°C -1 +1 % TA = 0°C +85°C OUT_ = GND EN_ = GND -2 +2 120 250 500 mA 3 5 8 kΩ IOUT_ = 1mA 1 IOUT_ = 50mA 25 IOUT_ = 100mA 50 mV 100 Line Regulation VIN_ = (VOUT_+ 0.1V) to 5.5V for VOUT_ ≥ 2.4V, or VIN_ = 2.5V to 5.5V for VOUT_ < 2.4V, IOUT = 1mA Output Voltage Noise 10Hz to 100kHz, COUT_ = 10µF ceramic, VOUT_ = 2.8V, IOUT_ = 10mA 45 µVRMS Output Voltage PSRR 100Hz, COUT_ = 2.2µF ceramic, IOUT_ = 10mA 67 dB Channel-to-Channel Isolation 10kHz, COUT_ = 2.2µF ceramic, IOUT_ = 10mA 64 dB 2 -0.15 +0.15 _______________________________________________________________________________________ %/V Integrated Cellular RF-Section Power-Management IC (VIN_ = 3.6V, EN_ = IN_, CIN = 6.8µF, COUT_ = 2.2µF, CBP = 0.01µF, all ceramic capacitors TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS ENABLE LOGIC CONTROL EN_ Input Threshold VEN_ 2.5V ≤ VIN_ ≤ 5.5V 0.4 1.6 V EN_ Input Bias Current IEN_ VEN_ = 5.5V or 0, TA = +85°C -1 +1 µA THERMAL PROTECTION Thermal Shutdown Temperature Thermal Shutdown Hysteresis TSHDN Rising temperature ∆TSHDN 160 °C 15 °C ELECTRICAL CHARACTERISTICS (VIN_ = 3.6V, EN_ = IN_, CIN = 6.8µF, COUT_ = 2.2µF, CBP = 0.01µF, all ceramic capacitors TA = -40°C to +85°C, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN MAX UNITS 2.5 5.5 V 2.10 2.45 V GENERAL Input Voltage VIN_ Input Undervoltage Lockout Threshold VUVLO Rising and Falling edge SUPPLY CURRENT Quiescent Supply Current IQ Shutdown Supply Current IOUT_ = 0 330 µA EN_ = OUT_ = GND 10 µA -2 +2 % 110 500 mA 3 8 kΩ 100 mV -0.15 +0.15 %/V LINEAR REGULATORS Output Voltage Accuracy Current Limit VOUT_ ILIM VIN_ = 0.5V + the highest of (VOUT1, VOUT2, or VOUT3), IOUT_ = 1mA to 100mA OUT_ = GND Output Pulldown Resistance ROUT_ EN_ = GND Dropout Voltage (Note 1) VIN_ VOUT_ IOUT_ = 100mA VIN_ = (VOUT_+ 0.1V) to 5.5V for VOUT_ ≥ 2.4V, or VIN_ = 2.5V to 5.5V for VOUT_ < 2.4V, IOUT = 1mA Line Regulation ENABLE LOGIC CONTROL EN_ Input Threshold VEN_ 2.5V ≤ VIN_ ≤ 5.5V 0.4 1.6 V EN_ Input Bias Current IEN_ VEN_ = 5.5V or 0, TA = +85°C -1 1 µA Note 1: The Dropout Voltage is defined as VIN_ - VOUT_, when VOUT_ is 100mV below the set output voltage (the value of VOUT_ for VIN_ = VOUT_ + 500mV). Since the minimum input voltage range is 2.5V, this specification is only meaningful when the set output voltage exceeds 2.7V (VOUT_(NOM) ≥ 2.7V). Note 2: Specifications to -40°C are guaranteed by design, not production tested. _______________________________________________________________________________________ 3 MAX8890 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (Circuit of Figure 1, MAX8890EGCGGG, VIN = 3.3V, EN_ = IN_, TA = +25°C, unless otherwise noted.) OUTPUT VOLTAGE vs. LOAD CURRENT 1.5 1.0 0.5 2.82 OUTPUT VOLTAGE (V) 2.0 2.83 MAX8890 toc02 2.82 OUTPUT VOLTAGE (V) 2.5 OUTPUT VOLTAGE (V) 2.83 MAX8890 toc01 3.0 OUTPUT VOLTAGE vs. TEMPERATURE 2.81 2.80 2.79 MAX8890 toc03 OUTPUT VOLTAGE vs. INPUT VOLTAGE 2.81 2.80 2.79 2.78 2.78 2.77 2.77 IOUT = 100mA IOUT = NO LOAD 4 5 0 60 80 GROUND-PIN CURRENT vs. INPUT VOLTAGE MAX8890 toc04 TA = +25°C 50 TA = +85°C 30 TA = -40°C 20 100 160 140 IOUT1 = 100mA 120 100 0 80 60 20 40 60 80 IOUT = NO LOAD 2 3 4 5 6 0 40 70 ISOLATION (dB) 50 40 10 50 85 100 50 40 30 20 CIN = 1µF + 0.1µF IOUT = 10mA LOW-IMPEDANCE INPUT IOUT1 = 100mA SINUSOIDAL LOAD IOUT3 = 10mA 10 0 60 80 60 20 IOUT1 = 100mA ONLY ONE OUTPUT ENABLED (EN1 = IN, EN2 = EN3 = GND) 60 80 MAX8890 toc08 70 PSRR (dB) 70 TEMPERATURE (°C) 20 CHANNEL-TO-CHANNEL ISOLATION 30 35 ONLY ONE OUTPUT ENABLED (EN1 = IN, EN2 = EN3 = GND) LOAD CURRENT (mA) 80 MAX8890 toc07 80 10 65 POWER-SUPPLY REJECTION RATIO 90 -15 70 50 1 60 -40 75 55 GROUND-PIN CURRENT vs. TEMPERATURE 60 80 60 0 100 85 85 INPUT VOLTAGE (V) 110 60 90 20 LOAD CURRENT (mA) 120 35 95 40 100 10 100 0 0 -15 GROUND-PIN CURRENT vs. LOAD CURRENT ONLY ONE OUTPUT ENABLED (EN1 = IN, EN2 = EN3 = GND) 180 -40 TEMPERATURE (°C) 200 10 4 40 DROPOUT VOLTAGE vs. LOAD CURRENT 60 40 20 LOAD CURRENT (mA) 70 DROPOUT VOLTAGE (mV) 6 MAX8890 toc06 3 MAX8890 toc09 2 INPUT VOLTAGE (V) MAX8890 toc05 1 GROUND-PIN CURRENT (µA) 0 GROUND-PIN CURRENT (µA) 0 GROUND-PIN CURRENT (µA) MAX8890 Integrated Cellular RF-Section Power-Management IC 0 0.01 0.1 1 10 FREQUENCY (kHz) 100 1000 0.1 1 10 FREQUENCY (kHz) _______________________________________________________________________________________ 100 1000 Integrated Cellular RF-Section Power-Management IC LOAD TRANSIENT LINE TRANSIENT RESPONSE LOAD TRANSIENT NEAR DROPOUT MAX8890 toc10 MAX8890 toc12 MAX8890 toc11 4.0V A A A 3.5V B B 20µs/div STARTUP WAVEFORM (CBP = 0.01µF) LOW-IMPEDANCE INPUT IOUT1 = 100mA SINUSOIDAL LOAD IOUT3 = 10mA MAX8890 toc13 1000 A. VIN = 3.5V to 4.0V, 200mV/div B. VOUT_ = 2.8V, 2mV/div IOUT = 100mA A. IOUT_ = 1mA to 100mA, 50mA/div B. VOUT_ = 2.8V, 20mV/div VIN = 2.9V (VOUT_ + 100mV) CROSSTALK VOLTAGE CROSSTALK (µVp-p) 40µs/div 20µs/div A. IOUT_ = 1mA to 100mA, 50mA/div B. VOUT_ = 2.8V, 20mV/div VIN = 3.3V (VOUT_ +500mV) B 2.8V STARTUP WAVEFORM (CBP = 0.1µF) MAX8890 toc14 MAX8890 toc15 A A B B C C 100 10 1 0.1 1 10 100 FREQUENCY (kHz) 1000 20µs/div A. VIN = 0 to 3.3V, 5V/div B. VOUT_ = 2.8V, 2V/div C. VBP = 1.25V, 1V/div ROUT_ = 28Ω (100mA) 5ms/div A. VIN = 0 to 3.3V, 5V/div B. VOUT_ = 2.8V, 2V/div C. VBP = 1.25V, 1V/div ROUT_ = 28Ω (100mA) _______________________________________________________________________________________ 5 MAX8890 Typical Operating Characteristics (continued) (Circuit of Figure 1, MAX8890EGCGGG, VIN = 3.3V, EN_ = IN_, TA = +25°C, unless otherwise noted.) MAX8890 Integrated Cellular RF-Section Power-Management IC Typical Operating Characteristics (continued) (Circuit of Figure 1, MAX8890EGCGGG, VIN = 3.3V, EN_ = IN_, TA = +25°C, unless otherwise noted.) ENABLE WAVEFORM (1ST OUTPUT) ENABLE WAVEFORM (2ND OUTPUT) MAX8890 toc16 MAX8890 toc17 A A B B C C D D 20µs/div A. VEN1 = 0 to 3.3V, 5V/div B. VOUT1 = 2.8V, ROUT1 = 28Ω (100mA), 2V/div C. VBP = 1.25V, 1V/div D. IIN, 200mA/div VIN = 3.3V, EN2 = EN3 = GND, CBP = 0.01µF 20µs/div A. VEN2 = 0 to 3.3V, 5V/div B. VOUT2 = 2.8V, ROUT2 = 28Ω (100mA), 2V/div C. VBP = 1.25V, 1V/div D. IIN, 200mA/div VIN = 3.3V, EN1 = IN, EN3 = GND, CBP = 0.01µF Pin Description 6 PIN NAME FUNCTION 1 IN1 Regulator 1 Input. Supply voltage can range from 2.5V to 5.5V. Bypass with a capacitor to GND (see Capacitor Selection and Regulator Stability). 2 IN2 Regulator 2 Input. Supply voltage can range from 2.5V to VIN1. Bypass with a capacitor to GND (see Capacitor Selection and Regulator Stability). 3 OUT2 Regulator 2 Output. Sources up to 100mA. Bypass with a 2.2µF ceramic capacitor to GND. 4 EN1 Active-High Enable Input for Regulator 1. A logic low shuts down the first linear regulator. In shutdown, OUT1 is pulled low through an internal 5kΩ resistor. Connect to IN1 for normal operation. 5 EN2 Active-High Enable Input for Regulator 2. A logic low shuts down the second linear regulator. In shutdown, OUT2 is pulled low through an internal 5kΩ resistor. Connect to IN2 for normal operation. 6 EN3 Active-High Enable Input for Regulator 3. A logic low shuts down the third linear regulator. In shutdown, OUT3 is pulled low through an internal 5kΩ resistor. Connect to IN3 for normal operation. 7 BP 8 GND 1.25V Voltage Reference Bypass Pin. Connect a 0.01µF ceramic bypass capacitor from BP to GND to minimize the output noise. Make no other connection to this pin. Ground. Connect both ground pins together externally, as close to the IC as possible. Regulator 3 Input. Supply voltage can range from 2.5V to VIN1. Bypass with a capacitor to GND (see Capacitor Selection and Regulator Stability). 9 IN3 10 OUT3 11 GND Ground. Connect both ground pins together externally, as close to the IC as possible. 12 OUT1 Regulator 1 Output. Sources up to 100mA. Bypass with a 2.2µF ceramic capacitor to GND. EXPOSED PAD GND Ground. THE EXPOSED PAD AND ALL FOUR CORNER TABS ON THE QFN PACKAGE ARE INTERNALLY CONNECTED TO GROUND. The exposed pad functions as a heatsink. Solder to a large pad or to the circuit board ground plane to maximize power dissipation. Do not use as device ground. Regulator 3 Output. Sources up to 100mA. Bypass with a 2.2µF ceramic capacitor to GND. _______________________________________________________________________________________ Integrated Cellular RF-Section Power-Management IC IN1 OUT1 IN2 OUT2 CIN 4.7µF OUTPUT #1 (1.8V TO 3.3V)* COUT1 2.2µF COUT2 2.2µF MAX8890 IN3 OUT3 EN1 BP MAX8890 INPUT 2.5V TO 5.5V OUTPUT #2 (1.8V TO 3.3V)* OUTPUT #3 (1.8V TO 3.3V)* COUT3 2.2µF ON OFF CBP 0.01µF EN2 EN3 GND *SEE THE Ordering Information AND Preset Output Voltage Suffixes SECTIONS Figure 1. Typical Application Circuit Detailed Description The MAX8890 is an RF power-management IC for a cellular phone. The MAX8890 contains three low-noise, low quiescent current, low-dropout, linear regulators for powering the transmitter, receiver, synthesizer, TCXO, and voltage controlled oscillators (VCOs). Each lowdropout linear regulator (LDO) supplies loads up to 100mA and is available with preset output voltages from 1.8V to 3.3V in 50mV increments. Furthermore, the MAX8890’s input voltage range of 2.5V to 5.5V is perfect for single-cell Li+ battery or 3-cell NiMH battery applications. As illustrated in Figure 2, each regulator consists of an error amplifier, internal feedback resistive-divider, and P-channel MOSFET pass transistor. The output voltage feeds back through the internal resistive-divider connected to OUT_. This feedback voltage connects to the error amplifier, which compares the feedback voltage with the internal 1.25V reference voltage and amplifies the difference. If the feedback voltage is lower than the reference voltage, the pass-transistor gate is pulled lower, which allows more current to flow to the output and increases the output voltage. If the feedback voltage is too high, the pass-transistor gate is pulled up, allowing less current to flow to the output. Clear transmission and reception in a cellular phone can only be achieved with a low-noise power supply. Therefore, all three LDOs on the MAX8890 feature low output voltage noise, high power-supply rejection ratios, and excellent load and line regulation characteristics. Designed for single-cell Li+ battery applications where a pulsed current demand is required from the battery, each LDO is designed with 45µVRMS noise from 10Hz to 100kHz and PSRR of 67dB. The MAX8890 also features output current limiting (short-circuit protection), a low-power shutdown mode, and thermal overload protection. Internal P-Channel Pass MOSFET Each linear regulator features a 0.5Ω P-channel MOSFET pass transistor. Unlike similar designs using PNP pass transistors, P-channel MOSFETs require no base drive, which reduces the quiescent current. PNP based regulators also waste considerable current in dropout when the pass transistor saturates and use high basedrive currents under large loads. The MAX8890 does not suffer from these problems and consumes only 180µA of quiescent current (all 3 regulators enabled). Current Limit (Short-Circuit Protection) The MAX8890 contains separate current-limit circuitry for each linear regulator. The device monitors and controls the gate voltage of each pass transistor, limiting the regulator’s output current to 250mA (typ). The output can be shorted to ground for an indefinite period of time without damage to the part as long as the maximum continuous power dissipation rating is not exceeded. Output Voltage Selection The MAX8890 is supplied with factory-set output voltages from 1.8V to 3.3V in 50mV increments. The threeletter part number suffix identifies the output voltage for each regulator. For example, the MAX8890EGCAKM’s output voltages are preset to 3.3V (V OUT1 ), 2.5V (VOUT2), and 1.8V (VOUT3). _______________________________________________________________________________________ 7 MAX8890 Integrated Cellular RF-Section Power-Management IC LINEAR REGULATOR #1 IN1 RSENSE OUT1 THERMAL SHDN ERROR AMPLIFIER CURRENT LIMIT CONTROL LOCIC IN1 EN1 BP REF 1.25V STARTUP CIRCUITRY GND IN2 LINEAR REGULATOR #2 OUT2 EN2 IN3 LINEAR REGULATOR #3 OUT3 EN3 Figure 2. Functional Diagram Enable If any one of the three low-dropout linear regulators (LDOs) is enabled, the internal 1.25V reference powers up. Therefore, all three LDOs must be disabled to shut down the internal reference, reducing the supply current to 0.01µA. Pull EN_ low to enter shutdown. When any one of the linear regulators is shutdown, the corresponding MAX8890 output disconnects from the corresponding input, and the output discharges through an internal 8 5kΩ resistor. The capacitance and load determine the rate at which VOUT_ decays. Do not leave EN_ floating. Connect EN_ to IN_ for normal operation. EN_ can be pulled as high as 6V, regardless of the input and output voltages. Thermal Overload Protection Thermal overload protection limits the MAX8890’s total power dissipation in the event of fault conditions. Each linear regulator has its own thermal shutdown circuitry. _______________________________________________________________________________________ Integrated Cellular RF-Section Power-Management IC Applications Information Capacitor Selection and Regulator Stability Capacitors are required at each input and each output of the MAX8890 for stable operation over the full load range and full temperature range. Connect a minimum 2.2µF ceramic capacitor between OUT_ and ground to ensure stability and optimum transient response. Use larger 10µF ceramic output capacitors for lower noise requirements. The input capacitor (CIN_) lowers the source impedance of the input supply, thereby reducing the input noise and improving transient response. Connect a minimum 1µF ceramic capacitance between each IN_ and ground. Place all input and output capacitors as close to the MAX8890 as possible to minimize the impact of PC board trace impedance. Because IN1 and IN2 are next to each other, they may easily share a single 2.2µF or larger ceramic capacitor. Surface-mount ceramic capacitors have very low ESR and are commonly available in values up to 10µF. However, note that some ceramic dielectrics exhibit large capacitance and ESR variation with temperature. Z5U and Y5V dielectrics may require a minimum 3.3µF nominal output capacitance, especially with low temperature operation. Noise, PSRR, and Transient Response The MAX8890 is designed to operate with low dropout voltages and low quiescent currents in battery-powered systems while providing low noise, fast transient response, and high AC rejection. See the Typical Operating Characteristics for a plot of Power-Supply Rejection Ratio (PSRR) vs. Frequency. When operating from noisy sources, improved supply-noise rejection and transient response can be achieved by increasing the values of the input and output bypass capacitors and through passive filtering techniques. The MAX8890 load-transient response graphs (see Typical Operating Characteristics) show two components of the output response: a DC shift from the output impedance due to the load current change and the transient response. Increasing the output capacitor’s value and decreasing the ESR reduces the transient under/overshoot. Input-Output (Dropout) Voltage A regulator’s minimum input-to-output voltage differential (dropout voltage) determines the lowest useable input supply voltage. Once the linear regulator reaches dropout, the series pass transistor is fully on and regulation ceases. The output voltage tracks the input voltage as the input voltage drops lower. Because the MAX8890 uses P-channel MOSFET pass transistors, its dropout voltage is a function of the MOSFET’s drain-tosource on-resistance (RDS(ON)) multiplied by the load current (see Typical Operating Characteristics): VDROPOUT = VIN_ - VOUT_ = RDS(ON) ✕ IOUT_ Reference Bypass Capacitor An external bypass capacitor is connected to BP to reduce the inherent reference noise. The capacitor forms a lowpass filter in conjunction with an internal network. Use a 0.01µF or greater ceramic capacitor connected as close to BP as possible. Capacitance values greater than 0.01µF will increase the startup time. (See Typical Operating Characteristics for startup waveforms.) For the lowest noise, increase the bypass capacitor to 0.1µF. Values above 0.1µF provide no performance improvement and are therefore not recommended. Do not place any additional loading on this reference bypass pin. _______________________________________________________________________________________ 9 MAX8890 When the junction temperature exceeds TJ = 160°C, a thermal sensor activates the shutdown logic, disabling the overheated regulator. The thermal sensor turns the linear regulator on again after the regulator’s junction temperature cools by 15°C, resulting in a pulsed output during continuous thermal-overload conditions. For continuous operation, do not exceed the absolute maximum junction-temperature rating of TJ = 150°C. Integrated Cellular RF-Section Power-Management IC MAX8890 Pin Configuration VERSION TOP VIEW IN1 IN2 TOP MARK OUT1 GND OUT3 MAX8890EGCAAA AAAA 12 11 10 MAX8890EGCDDD AAAC MAX8890EGCGGG AAAE 1 9 2 MAX8890 OUT2 Standard Versions 3 4 5 6 EN1 EN2 EN3 IN3 8 GND 7 BP MAX8890EGCMMM AAAJ MAX8890EGCAKM AAAK Chip Information TRANSISTOR COUNT: 1472 PROCESS: BiCMOS 4 ✕ 4 QFN 10 ______________________________________________________________________________________ Integrated Cellular RF-Section Power-Management IC 12, 16,20, 24L QFN.EPS ______________________________________________________________________________________ 11 MAX8890 Package Information Integrated Cellular RF-Section Power-Management IC MAX8890 Package Information (continued) 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. 12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.