GM6155 150mA LOW - NOISE LDO REGULATOR Power Management Features Description Very low noise output The GM6155 is an efficient linear voltage regulator with ultralow - noise output, very low dropout voltage (typically 17mV at light loads and 100mV at 50mA), and very low ground current (600µA at 100mA output). The GM6155 provides better than 1% initial accuracy. Extremely accurate output voltage Guaranteed 150mA output Low quiescent current Low dropout voltage Extremely tight load and line regulation Designed especially for hand-held, battery-powered de- Very low temperature coefficient vices, the GM6155 includes a CMOS or TTL compatible en- Current and thermal limiting able/ shutdown control input. When shutdown, power con- Reverse-battery protection sumption drops nearly to zero. Regulator ground current in- "Zero" off-mode current creases only slightly in dropout, further prolonging battery Logic-controlled electronic enable life. Key GM6155 features include a reference bypass pin to improve its already excellent low-noise performance, reversed-battery protection, current limiting, and overtemperature shutdown. The GM6155 is available in SOT-25 package. Application Cellular telephones Consumer/ personal electronics Laptop, notebook, and palmtop computers SMPS post-regulator/ dc-to-dc modules Battery-powered equipment High-efficiency linear power supplies PCMCIA VCC and VPP regulation/ switching 2 Enable Shutdown 3 5 VOUT COUT = 2.2µF (tantalum) 4 EN CBYP EN (pin 3) may be connected directly to IN (pin1). Revision 1, Feb. 2004 1 Low-Noise Operation: CBYP = 470pF, COUT Basic Operation: CBYP = not used, COUT 2.2µF 1µF www.gammamicro.com PRELIMINARY GM6155 VIN GM6155-3.3 TYPICAL APPLICATION CIRCUITS 1 GM6155 MARKING INFORMATION & PIN CONFIGURATIONS (TOP VIEW) SOT-25 (SOT-23-5) SOT-25 (SOT-23-5) OUT BYP OUT ADJ 5 4 5 4 XXVYW 2 1 Part Identification XXVYW 3 1 2 3 IN GND EN IN GND EN Fixed Voltages Adjustable Voltage XX V Y W = Specific Device Code(DA = GM6155) = Voltage Code = Year = Work Week ORDERING INFORMATION Output Voltage Voltage Code Ordering Number Package Shipping Adj A SOT-25 3,000 Units/ Tape & Reel GM6155-2.5ST25R 2.5V G SOT-25 3,000 Units/ Tape & Reel GM6155-2.7ST25R 2.7V T SOT-25 3,000 Units/ Tape & Reel GM6155-2.8ST25R 2.8V H SOT-25 3,000 Units/ Tape & Reel GM6155-2.9ST25R 2.9V X SOT-25 3,000 Units/ Tape & Reel GM6155-3.0ST25R 3.0V J SOT-25 3,000 Units/ Tape & Reel GM6155-3.3ST25R 3.3V K SOT-25 3,000 Units/ Tape & Reel GM6155-3.6ST25R 3.6V L SOT-25 3,000 Units/ Tape & Reel GM6155-4.0ST25R 4.0V M SOT-25 3,000 Units/ Tape & Reel GM6155-4.2ST25R 4.2V Y SOT-25 3,000 Units/ Tape & Reel GM6155-5.0ST25R 5.0V Q SOT-25 3,000 Units/ Tape & Reel GM6155-AST25R * For detail Ordering Number identification, please see last page. GM6155 PIN DESCRIPTION 2 Function Pin Number Pin Name 1 IN 2 GND 3 EN Enable/ Shutdown(Input): COMS compatible input. Logic high = enable, logic low or open = shutdown. 4 BYP Reference Bypass: Connect external 470pF capacitor to GND to reduce output noise. May be left open. 5 OUT Regulator Output Supply Input Ground GM6155 BLOCK DIAGRAM VOUT OUT IN VIN + BYP CBYP (Optional) COUT + - Bandgap Ref. EN Current Limit Thermal Shutdown VIN OUT IN + GND ADJ R2 Figure 1. Ultra-Low-Noise Fixed Regulator Bandgap Ref. EN COUT R1 + VOUT CBYP (Optional) VOUT = VREF (1 + R2/ R1) Current Limit Thermal Shutdown GND Figure 2. Ultra-Low-Noise Adjustable Regulator ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL RATINGS UNITS Supply Input Voltage VIN -20 ~ + 20 V Enable Input Voltage VEN -20 ~ +20 V Power Dissipation (Note 3) PD Internally Limited W Junction Temperature TJ -40 ~ +125 °C TLEAD 260 °C TS -60 ~ +150 °C Lead Temperature (soldering, 5 seconds) Storage Temperature PARAMETER SYMBOL RATINGS UNITS Supply Input Voltage VIN +2.5 to +16 V Enable Input Voltage VEN 0 to VIN V Junction Temperature TJ -40 ~ + 125 °C Thermal Resistance qJA (Note 3) °C/ W GM6155 OPERATING RATINGS 3 GM6155 ELECTRICAL CHARACTERISTICS (VIN = VOUT + 1V; IL = 100µA; CL = 1.0µF; VEN unless otherwise noted) 2.0; TJ = 25°C, bold values indicate -40°C TJ +125°C; Typ Symbol Test Condition Min VO Variation from specified VOUT -1 -2 Output Voltage Temperature Coefficient DVO/ DT (Note 4) 100 Line Regulation DVO/ VO VIN = VOUT + 1V to 16V 0.004 0.012/ 0.05 %/ V Load Regulation DVO/ VO IL = 0.1mA to 150mA, (Note 5) 0.02 0.2/ 0.5 %/V IL = 100µA 10 IL = 50mA 110 IL = 100mA 140 IL = 150mA 165 50 70 150 230 250 300 275 350 1 Parameter Output Voltage Accuracy Dropout Voltage (Note 6) Quiescent Current Ground Pin Current (Note 7) VIN - VO IGND VEN 0.01 0.4V (shutdown) Unit 1 2 % ppm/ °C mV µA VEN 0.18V (shutdown) VEN 2.0V, IL = 0.1mA IGND Max 80 IL = 50mA 350 IL = 100mA 600 IL = 150mA 1300 5 125 150 600 800 1000 1500 1900 2500 µA Ripple Rejection PSRR f = 100Hz, IL = 0.1mA 75 Current Limit ILIMT VOUT = 0V 320 (Note 8) 0.05 %/ W 260 nV/ Hz Thermal Regulation Output Noise DVO/ DPD eNO IL = 50mA, CL = 2.2µF, 470pF from BYP to GND dB 500 mA ENABLE Input Enable Input Logic-Low Voltage VIL Regulator shutdown Enable Input Logic-High Voltage VIH Regulator enabled IIL Enable Input Current GM6155 IIH 4 VIL 0.4V VIL 0.18V VIH 2.0V 0.4 0.18 2.0 2 V V 0.01 -1 -2 µA 5 20 25 µA Note 1. Exceeding the absolute maximum rating may damage the device. Note 2. The device is not guaranteed to function outside its operating rating. Note 3: The maximum allowable power dissipation at any TA (ambient temperature) is PD(max) = (TJ(max) -TA) qJA. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. Note 4: Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range. Note 5: Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification. Note 6: Dropout Voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1V differential. Note 7: Ground pin current is the regulator quiescent current plus pass transistor base current. The total current drawn from the supply is the sum of the load current plus the ground pin current. Note 8: Thermal regulation is defined as the change in output voltage at a time "t" after a change in power dissipation is applied, excluding load or line regulation effects. Specifications are for a 150mA load pulse at VIN = 16V for t = 10ms. GM6155 Applications Information Enable/ Shutdown Forcing EN (enable/ shutdown) high (>2V) enables the regulator. EN is compatible with CMOS logic gates. If the enable / shutdown feature is not required, connect EN (pin 3) to IN (supply input, pin 1). See Figure 3. Input Capacitor A 1µF capacitor should be placed from IN to GND if there is more than 10 inches of wire between the input and the acfilter capacitor or if a battery is used as the input . Reference Bypass Capacitor BYP (reference bypass) is connected to the internal voltage reference. A 470pF capacitor (CBYP) connected from BYP to GND quiets this reference, providing a significant reduction in output noise. CBYP reduces the regulator phase margin; when using CBYP, output capacitors of 2.2µF or greater are generally required to maintain stability. The start-up speed of the GM6155 is inversely proportional to the size of the reference bypass capacitor. Applications requiring a slow ramp-up of output voltage should consider larger values of CBYP. Likewise, if rapid turn-on is necessary, consider omitting CBYP. If output noise is not a major concern, omit CBYP and leave BYP open. Output Capacitor An output capacitor required between OUT and GND to prevent oscillation. The minimum size of the output capacitor is dependent upon whether a reference bypass capacitor is used. 1.0µF minimum is recommended when CBYP is not used (see Figure 2). 2.2µF minimum is recommended when CBYP is 470pF (see Figure 1). Larger values improve the regulator's transient response. The output capacitor value may be increased without limit. The output capacitor is should have an ESR (effective series resistance) of about 5W or less and a resonant frequency above 1MHz. Ultra-low-ESR capacitors can cause a low amplitude oscillation on the output and/ or underdamped transient response. Most tantalum or aluminum electrolytic capacitors are adequate; film types will work, but are more expensive. Since many aluminum electrolytics have electrolytes that freeze at about -30°C, solid tantalums ate recommended for operation below -25°C. At lower values for output current, less output capacitance is required for output stability. The capacitor can be reduced to 0.47µF for current below 10mA or 0.33µF for current below 1mA. No-Load Stability The GM6155 will remain stable and in regulation with no load (other than the internal voltage divider) unlike many other voltage regulators. This is especially important in CMOS RAM keep-alive applications. Thermal Considerations PD(max) = (TJ(max) - TA) RqJA TJ(max) is the maximum junction temperature of the die, 125°C, and TA is the ambient operating temperature. RqJA is layout dependent; Table 1 shows examples of junction-to-ambient thermal resistance for the GM6155. GM6155 The GM6155 is designed to provide 150mA of continuous current in a very small package. Maximum power dissipation can be calculated based on the output current and the voltage drop across the part. To determine the maximum power dissipation of the package, use the junction-to-ambient thermal resistance of the device and the following basic equation: 5 GM6155 Parameter RqJA Recommended Minimum Footprint RqJA 1" Square 220°C/ W 170°C/ W SOT-23-5 RqJC Copper Clad 130°C/ W Table 1. SOT-25 Thermal Resistance The actual power dissipation of the regulator circuit can be determined using the equation: PD = (VIN - VOUT) IOUT + VIN IGND Substituting PD(max) for PD and solving for the operating conditions that are critical to the application will give the maximum operating conditions for the regulator circuit. For example, when operating the GM6155 at room temperature with a minimum footprint layout, the maximum input voltage for a set output current can be determined as follows: (125°C - 25°C) PD(max) = 220°C/W PD(max) = 455mW The junction-to-ambient thermal resistance for the minimum footprint is 220°C/ W, from Table 1. The maximum power dissipation must not be exceeded for proper operation. Using the output voltage of 3.3V and an output current of 150mA, the maximum input voltage can be determined. From the Electrical Characteristics table, the maximum ground current for150mA output current is 2500µA or 2.5mA. 455mW = (VIN - 3.3V) 150mA + VIN • 2.5mA 455mW = VIN • 150mA - 495mA + VIN • 2.5mA 950mW = VIN • 152.5mA VIN(max) = 6.23V Therefore, a 3.3V application at 150mA of output current can accept a maximum input voltage of 6.2V in a SOT-25 package. For a full discussion of heat sinking and thermal effects on voltage regulators. Fixed Regulator Applications 1 2 3 5 Figure 4. Low-Noise Fixed Voltage Application VOUT VIN 2.2µF 2 Enable Shutdown 4 GM6155 470pF 6 Figure 3. includes a 470pF capacitor for low-noise operation and shows EN (pin 3) connected to IN (pin 1) for an application where enable/ shutdown is not required. COUT = 2.2µF minimum. 1 3 GM6155 VIN GM6155 Figure 3. Ultra-Low-Noise Fixed Voltage Application 5 VOUT 1.0µF 4 EN Figure 4. is an example of a low-noise configuration where CBYP is not required. C OUT = 1µF minimum. Adjustable Regulator Applications The GM6155 can be adjusted to a specific output voltage by using two externa resistors (Figure 5). The resistors set the output voltage based on the following equation: VOUT = 1.242V X ( R2 +1) R1 GM6155 VIN 1 2 3 GM6155-Adj This equation is correct due to the configuration of the bandgap reference. The bandgap voltage is relative to the output, as seen in the block diagram. Traditional regulators normally have the reference voltage relative to ground and have a different VOUT equation. Resistor values ate not critical because ADJ(adjust) has a high input impedance, but for best results use resistors of 470kW or less. A capacitor from ADJ to ground provides greatly improved noise performance. VOUT 5 2.2µF R1 4 R2 470pF Figure 5. Ultra-Low- Noise Adjustable Voltage Application Figure 5 includes the optional 470pF noise bypass capacitor from ADJ to GND to reduce output noise. Dual-Supply Operation When used in dual supply systems where the regulator load is returned to a negative supply, the output voltage must be diode clamped to ground. Typical Characteristics 0 V = 6V IN VOUT = 5V 0 V = 6V IN VOUT = 5V -20 PSRR (dB) -40 -60 -80 IOUT =100mA COUT = 1µF 100 1k 10k 100k 1M -100 10 10M IOUT =100mA COUT = 2.2µF CBYP = 0.01µF 100 1k 10k 100k 1M 10M FREQUENCY(Hz) FREQUENCY(Hz) Figure 6. Power Supply Rejection Ratio Figure 7. Power Supply Rejection Ratio 320 10 280 125°C 1 240 200 NOISE (µV/ Hz) DROPOUT VOLTAGE (mV) -60 -80 -100 10 25°C 160 -40°C 120 80 40 0 0 -40 40 80 120 OUTPUT CURRENT (mA) Figure 8. Dropout Voltage vs. Output Current 160 100mA 0.1 10mA 0.01 VOUT=5V 0.001 COUT=10µF electrolytic CBYP=10nF 0.0001 10 100 1k 1mA 10k 100k 1M FREQUENCY(Hz) Figure 9. Noise Performance 10M GM6155 PSRR (dB) -20 7 GM6155 SOT-25(SOT-23-5) PACKAGE OUTLINE DIMENSIONS 2.9 ± 0.1 1.9 ± 0.05 0.13 0.95 ± 0.038 Pad Layout 0.028 0.7 0~0.1 0.15 ± 0.05 2.8 ± 0.1 F 0.094 2.4 0.65 ± 0.05 0.35 ± 0.03 5° 0.8 ± 0.05 0.037 0.095 0.074 1.9 5° 1.10 ± 0.1 0.037 0.095 ( Inches mm ) Unit:mm ORDERING NUMBER GM 6155 A ST25 R Gamma Micro. Shipping R: Tape & Reel GM6155 Circuit Type 8 Output Voltage A: Adj, 2.5: 2.5V 2.7: 2.7V, 2.8: 2.8V 2.9: 2.9V, 3.0: 3.0V 3.3: 3.3V, 3.6: 3.6V 4.0: 4.0V, 4.2: 4.2V Package ST25: SOT-25