RP122 3mA, Ultra-Low Noise, Ultra-Fast CMOS LDO Regulator General Description The RP122 is designed for portable RF and wireless applications with demanding performance and space requirements. The RP122 performance is optimized for battery-powered systems to deliver ultra low noise and low quiescent current. A noise bypass pin is available for further reduction of output noise. Regulator ground current increases only slightly in dropout, further prolonging the battery life. The RP122 also works with low-esr ceramic capacitors, reducing the amount of board space necessary for power applications, critical in hand-held wireless devices. The RP122 consumes less than.1µa in shutdown mode and has fast turn-on time less than µs. The other features include ultra low dropout voltage, high output accuracy, current limiting protection, and high ripple 23 packages. Ordering Information rejection ratio. Available in the -lead of SC-7 and SOT- RP122- Package Type U: SC-7- B : SOT-23- Operating Temperature Range G: Green ( Halogen Free with Commercial Standard 1 : 1.V 16 : 1.6V : 34 : 3.4V 3 : 3.V 1H : 1.8V 2H : 2.8V Features Ultra-Low-Noise for RF Application Ultra-Fast Response in Line/Load Transient Quick Start-Up (Typically µs) <.1µA Standby Current When Shutdown Low Dropout : 22mV @ 3mA Wide Operating Voltage Ranges : 2.V to.v TTL-Logic-Controlled Shutdown Input Low Temperature Coefficient Current Limiting Protection Thermal Shutdown Protection Only 1µF Output Capacitor Required for Stability High Power Supply Rejection Ratio Custom Voltage Available RoHS Compliant and 1% Lead (Pb)-Free Applications CDMA/GSM Cellular Handsets Battery-Powered Equipment Laptop, Palmtops, Notebook Computers Hand-Held Instruments PCMCIA Cards Portable Information Appliances Marking Information For marking information, contact our sales representative directly or through a Richpower distributor located in your area. Pin Configurations (TOP VIEW) Note : VIN 1 VOUT Richpower Green products are : RoHS compliant and compatible with the current GND 2 requirements of IPC/JEDEC J-STD-2. Suitable for use in SnPb or Pb-free soldering processes. EN 3 4 BP SC-7-/SOT-23- RP122-4 Dec 29 1
RP122 Typical Application Circuit RP122 V IN C IN 1uF + VIN GND VOUT + C OUT 1uF VOUT Chip Enable EN BP C BP 22nF Functional Pin Description Pin Name Pin Function VIN GND EN BP VOUT Power Input Voltage Ground Chip Enable (Active High). Note that this pin is high impedance. There should be a pull low 1KΩ resistor connected to GND when the control signal is floating. Reference Noise Bypass Function Block Diagram EN Quick Start Shutdown and Logic Control VIN BP V REF + - Error Amplifier MOS Driver Current-Limit and Thermal Protection VOUT GND 2 RP122-4 Dec 29
Absolute Maximum Ratings (Note 1) RP122 Supply Input Voltage ---------------------------------------------------------------------------------------------------- 6V Power Dissipation, P D @ T A = 2 C SC-7- -------------------------------------------------------------------------------------------------------------------- 3mW SOT-23- ------------------------------------------------------------------------------------------------------------------- 4mW Package Thermal Resistance (Note 4) SC-7-, θ JA --------------------------------------------------------------------------------------------------------------- 333 C/W SOT-23-, θ JA ------------------------------------------------------------------------------------------------------------- 2 C/W Lead Temperature (Soldering, 1 sec.) ----------------------------------------------------------------------------- 26 C Storage Temperature Range ------------------------------------------------------------------------------------------- 6 C to 1 C Operation Temperature Range ---------------------------------------------------------------------------------------- 4 C to 8 C ESD Susceptibility (Note 2) HBM (Human Body Mode) -------------------------------------------------------------------------------------------- 2kV MM (Machine Mode) ---------------------------------------------------------------------------------------------------- 2V Recommended Operating Conditions (Note 3) Supply Input Voltage ---------------------------------------------------------------------------------------------------- 2.V to.v Electrical Characteristics (V IN = V OUT + 1V, C IN = C OUT = 1µF, C BP = 1nF, T A = 2 C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Units Accuracy V OUT I OUT = 1mA 2 -- +2 % Current Limit I LIM R LOAD = 1Ω 36 4 -- ma Quiescent Current I Q V EN 1.2V, I OUT = ma -- 9 13 µa Dropout Voltage (Note ) V DROP Line Regulation V LINE I OUT = 2mA 17 2 I OUT = 3mA -- 22 3 V IN = (V OUT +.3V) to.v, I OUT = 1mA mv -- --.3 % Load Regulation V LOAD 1mA < I OUT < 3mA -- --.6 % Standby Current I STBY V EN = GND, Shutdown --.1 1 µa EN Input Bias Current I IBSD V EN = GND or VIN -- 1 na EN Threshold Output Noise Voltage Power Supply Rejection Rate Logic-Low Voltage V IL V IN = 3V to.v, Shutdown -- --.4 Logic-High Voltage V IH V IN = 3V to.v, Start-Up 1.2 -- -- e NO 1Hz to 1kHz, I OUT = 2mA C OUT = 1µF V -- 1 -- µv RMS f = 1Hz -- 7 -- PSRR C OUT = 1µF, I OUT = 1mA f = 1kHz -- -- Thermal Shutdown Temperature T SD -- 16 -- C Thermal Shutdown Temperature Hysteresis T SD -- 3 -- C db RP122-4 Dec 29 3
RP122 Note 1. Stresses listed as the above "Absolute Maximum Ratings" may cause permanent damage to the device. These are for stress ratings. 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 remain possibility to affect device reliability. Note 2. Devices are ESD sensitive. Handling precaution recommended. Note 3. The device is not guaranteed to function outside its operating conditions. Note 4. θja is measured in the natural convection at TA = 2 C on a low effective thermal conductivity test board (Single Layer, 1S) of JEDEC 1-3 thermal measurement standard. Note. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) 1mV. 4 RP122-4 Dec 29
RP122 Typical Operating Characteristics (V) 1.8 1.7 1.6 1. 1.4 1.3 vs. Temperature RP122-1PB VIN = 3.3V CIN = COUT = 1uF X7R Quiescent Current (ua) 9 9 8 8 7 7 6 Quiescent Current vs. Temperature RP122-1PB VIN = 3.3V CIN = COUT = 1uF X7R 1.2 - -2 2 7 1 12 Temperature ( C) 6 - -2 2 7 1 12 Temperature ( C) Dropout Voltage (mv) 3 2 2 1 1 Dropout Voltage vs. Temperature RP122-33PB CIN = COUT = 1uF PSRR (db) 2-2 -4-6 VIN = 4V to V CIN = COUT = 1uF, X7R PSRR ILoad = 1mA ILoad = 1mA..1.1.2.2.3 Load Current (A) -8.1 1 1.1 1K 1 1K 1K 1 1M Frequency (khz) (Hz) EN Pin Shoutdown Threshold (V) EN Pin Shoutdown Threshold vs. Temperature 1.7 1. 1.2 1.7 RP122-1PB VIN = 3.3V CIN = COUT = 1uF X7R. - -2 2 7 1 12 Temperature ( C) EN Pin Voltage (V) (V) 1 2 1 EN Pin Shutdown Response VIN = V CIN = COUT = 1uF Time (µs/div) RP122-28PB No Load RP122-4 Dec 29
RP122 Load Transient Response Load Transient Response Load Current (ma) 1 VIN = V, VOUT = 2.8V CIN = COUT = 1uF RP122-1PB ILoad = 1mA to 6mA Load Current (ma) 4 2 VIN = V, VOUT = 2.8V CIN = COUT = 1uF RP122-1PB ILoad = 1mA to 2mA Deviation (mv) 2-2 Deviation (mv) - Time (µs/div) Time (µs/div) Line Transient Response Line Transient Response Input Voltage Deviation (V) 6 4 VIN = 4V to V COUT = 1uF RP122-2PB ILoad = 1mA Input Voltage Deviation (V) 6 4 VIN = 4V to V COUT = 1uF RP122-2PB ILoad = 1mA Deviation (mv) 1-1 Deviation (mv) 1-1 Time (µs/div) Time (1µs/Div) Noise Noise VIN = 4.V CIN = COUT = 1uF, X7R RP122-3PB ILoad = ma VIN = 4.V CIN = COUT = 1uF, X7R RP122-1PB ILoad = ma 2 2 Noise (µv) 1-1 Noise (µv) 1-1 -2-2 Time (1ms/Div) f = 1Hz to 1kHz Time (1ms/Div) f = 1Hz to 1kHz 6 RP122-4 Dec 29
RP122 Start Up EN Pin Voltage (V) 1 VIN = V CIN = COUT = 1uF RP122-28PB No Load (V) 2 1 Time (1µs/Div) RP122-4 Dec 29 7
RP122 Applications Information Like any low-dropout regulator, the external capacitors used with the RP122 must be carefully selected for regulator stability and performance. Using a capacitor whose value is > 1µF on the RP122 input and the amount of capacitance can be increased without limit. The input capacitor must be located a distance of not more than. inch from the input pin of the IC and returned to a clean analog ground. Any good quality ceramic or tantalum can be used for this capacitor. The capacitor with larger value and lower ESR (equivalent series resistance) provides better PSRR and line-transient response. The output capacitor must meet both requirements for minimum amount of capacitance and ESR in all LDOs application. The RP122 is designed specifically to work with low ESR ceramic output capacitor in space-saving and performance consideration. Using a ceramic capacitor whose value is at least 1µF with ESR is > 2mΩ on the RP122 output ensures stability. The RP122 still works well with output capacitor of other types due to the wide stable ESR range. Figure 1 shows the curves of allowable ESR range as a function of load current for various output capacitor values. Output capacitor of larger capacitance can reduce noise and improve load transient response, stability, and PSRR. The output capacitor should be located not more than. inch from the V OUT pin of the RP122 and returned to a clean analog ground. COUT ESR (Ω) 1. 1. 1. 1.1.1. Region of Stable C OUT ESR vs. Load Current Instable Stable Instable 1 1 2 2 3 Load Current (ma) Figure 1 RP122-1PB CIN = COUT = 1uF, X7R Bypass Capacitor and Low Noise Connecting a 22nF between the BP pin and GND pin significantly reduces noise on the regulator output, it is critical that the capacitor connection between the BP pin and GND pin be direct and PCB traces should be as short as possible. There is a relationship between the bypass capacitor value and the LDO regulator turn on time. DC leakage on this pin can affect the LDO regulator output noise and voltage regulation performance. Enable Function The RP122 features an LDO regulator enable/disable function. To assure the LDO regulator will switch on, the EN turn on control level must be greater than 1.2 volts. The LDO regulator will go into the shutdown mode when the voltage on the EN pin falls below.4 volts. For to protecting the system, the RP122 have a quick-discharge function. If the enable function is not needed in a specific application, it may be tied to V IN to keep the LDO regulator in a continuously on state. Thermal Considerations Thermal protection limits power dissipation in RP122. When the operation junction temperature exceeds 16 C, the OTP circuit starts the thermal shutdown function turn the pass element off. The pass element turn on again after the junction temperature cools by 3 C. For continue operation, do not exceed absolute maximum operation junction temperature 12 C. The power dissipation definition in device is: P D = (V IN V OUT ) x I OUT + V IN x I Q The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surroundings airflow and temperature difference between junction to ambient. The maximum power dissipation can be calculated by following formula: P D(MAX) = ( T J(MAX) T A ) /θ JA Where T J(MAX) is the maximum operation junction temperature 12 C, T A is the ambient temperature and the θ JA is the junction to ambient thermal resistance. 8 RP122-4 Dec 29
RP122 For recommended operating conditions specification of RP122, where T J(MAX) is the maximum junction temperature of the die (12 C) and T A is the maximum ambient temperature. The junction to ambient thermal resistance (θ JA is layout dependent) for SOT-23- package is 2 C/W on standard JEDEC 1-3 thermal test board. The maximum power dissipation at T A = 2 C can be calculated by following formula: P D(MAX) = (12 C 2 C) / 333 = 3mW (SC-7-) P D(MAX) = (12 C 2 C) / 2 = 4mW (SOT-23-) The maximum power dissipation depends on operating ambient temperature for fixed T J(MAX) and thermal resistance θ JA. RP122-4 Dec 29 9
RP122 Outline Dimension D H L C B b A e A1 Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A.8 1.1.31.44 A1..1..4 B 1.1 1.3.4.4 b.1.4.6.16 C 1.8 2.4.71.96 D 1.8 2.2.71.89 e.6.26 H.8.26.3.1 L.21.46.8.18 SC-7- Surface Mount Package 1 RP122-4 Dec 29
RP122 D H L C B b A e A1 Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A.889 1.29.3.1 A1..12..6 B 1.397 1.83..71 b.36.9.14.22 C 2.91 2.997.12.118 D 2.692 3.99.16.122 e.838 1.41.33.41 H.8.24.3.1 L.3.61.12.24 SOT-23- Surface Mount Package RICHPOWER MICROELECTRONICS CORP. Headquarter Room 212, 177 ZuChongZhi Road, Zhang Jiang Hi-TechPark, Pudong New Area, Shanghai, China Tel: (8621)27777 Fax: (8621)276966 Information that is provided by Richpower Technology Corporation is believed to be accurate and reliable. Richpower reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be guaranteed by users when integrating Richpower products into any application. No legal responsibility for any said applications is assumed by Richpower. RP122-4 Dec 29 11