SY8009 SILERGY | Alldatasheet

Document overview

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Technical content

Features

  • Low R DS(ON) for internal switches (top/bottom)
  • SY8009A: 180m Ω/120mΩ, 1.5A, SOT23-5
  • SY8009B:100m Ω/80mΩ,2.0A SOT23-6, SSOT23-6
  • 3-5.5V input voltage range
  • High switching frequency minimizes the external components
  • SY8009A: 1.5MHz
  • SY8009B: 1MHz
  • Internal softstart limits the inrush current
  • 100% dropout operation
  • RoHS Compliant and Halogen Free
  • Compact package: SOT23-5, SOT23-6 and Super SOT23-6 are pin-compatible. Other packages are available upon requests

Applications

  • LCD TV
  • Set Top Box
  • Net PC
  • Mini-Notebook PC
  • Access Point Router Typical Applications IN GND EN CIN VIN ON/ OFF LX FB COUT VOUT L C1(opt.) Load Current (A) Efficiency (%) 0 0.4 0.8 1.2 1.6 2 VIN=3.3V VIN=4.2V VIN=5.5V VOUT=1.8V Figure 1.Schematic diagram Figure 2. Efficiency vs Load Current

AN_SY8009 AN_SY8009 Rev. 0.71 Silergy Corp. Confidential- Prepared for Internal Use Only 2 Pinout (top view) 3 4 6EN GND LX FB NC IN SOT23-5(SY8009A) SOT23-6(SY8009B) SSOT23-6(SY8009B) Part Number Package type Top Mark SY8009AAAC SOT23-5 AD xyz SY8009BABC SOT23-6 CU xyz SY8009BEBC SSOT23-6 AS xyz Note x=year code, y=week code, z= lot number code. Pin Name Pin Number Pin Description EN 1 Enable control. Pull high to turn on. Do not f loat. GND 2 Ground pin LX 3 Inductor pin. Connect this pin to the switchin g node of inductor. IN 4 Input pin. Decouple this pin to GND pin with a t least 1uF ceramic cap. FB 6 （SY8009B ） Output Feedback Pin. Connect this pin to the center point of the output resistor divider (as shown in Figure 1) to program the output voltage: V OUT =0.6*(1+R Absolute Maximum Ratings (Note 1) IN + 0.6V Power Dissipation, P D @ T A = 25°C, Package Thermal Resistance (Note 2) SOT23-5, SOT23-6, SSOT23-6, θ JA SOT23-5, SOT23-6, SSOT23-6, θ JC 65°C to 150°C ESD Susceptibility (Note 2) Recommended Operating Conditions (Note 3) 40°C to 125°C 40°C to 85°C

AN_SY8009 AN_SY8009 Rev. 0.71 Silergy Corp. Confidential- Prepared for Internal Use Only 3

Electrical Characteristics

= 5V, V OUT = 2.5V, L = 2.2uH, C OUT = 10uF, T A = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Input Voltage Range V IN 3 5.5 V Quiescent Current I Q I OUT= V FB REF 105% 80 µA Shutdown Current I SHDN EN=0 0.1 1 µA Feedback Reference Voltage V REF 0.588 0.6 0.612 V FB Input Current I FB V FB IN -50 50 nA SY8009A 180 m Ω PFET RON R DS(ON) P SY8009B 100 m Ω SY8009A 120 m Ω NFET RON R DS(ON) N SY8009B 80 m Ω SY8009A 1.8 A PFET Current Limit I LIM SY8009B 2.5 A EN Rising Threshold V ENH 1.5 V EN Falling Threshold V ENL 0.4 V Input UVLO Threshold V UVLO 2.7 V UVLO Hysteresis V HYS 0.1 V I OUT =200mA, SY8009A 1.5 MHz Oscillator Frequency F OSC I OUT =500mA, SY8009B 1 MHz Min ON Time 50 ns Max Duty Cycle 100 % Thermal Shutdown Temperature TSD 160 °C 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: θ JA is measured in the natural convection at TA = 25°C on a low effective single layer thermal conductivity test board of JEDEC 51-3 thermal measurement standard. Pin 2 of SOT23-5/SOT23-6/SSOT23-5 packages is the case position for θ JC measurement. Note 3: The device is not guaranteed to function outside its operating conditions.

AN_SY8009 AN_SY8009 Rev. 0.71 Silergy Corp. Confidential- Prepared for Internal Use Only 4 Typical Performance Characteristics (SY8009B) Efficiency vs Load Current Efficiency vs Load Curre nt Efficiency vs Load Current Output Ripple (Vin=5.0V, Vout=1.8V,Iload=0.5A) Output Ripple (Vin=5.0V, Vout=1.8V,Iload=1.5A) Output Ripple (Vin=5.0V, Vout=1.8V,Iload=2A) Startup (Vin=5.0V, Vout=1.8V,Iload=2A) Shutdown (Vin=5.0V, Vout=1.8V,Iload=2A)

AN_SY8009 AN_SY8009 Rev. 0.71 Silergy Corp. Confidential- Prepared for Internal Use Only 5 Soft Start(Vo) Soft Start(Lx) Load Transient (Vin=5.0VmVout=1.8V,Iload=0~1A) Load Transient (Vin=5.0V, Vout=1.8V,Iload=0.2~2A) Oscillator Frequency vs Vin Case Temperature vs Output Current (Vin=5V,Vo=1.8V,Ta=27 )℃ TC(°C)

AN_SY8009 AN_SY8009 Rev. 0.71 Silergy Corp. Confidential- Prepared for Internal Use Only 6 Operation SY8009 is a synchronous buck regulator IC that integrates the PWM control, top and bottom switches on the same die to minimize the switching transition loss and conduction loss. With ultra low R DS(ON) power switches and proprietary PWM control, this regulator IC can achieve the highest efficiency and the highest switch frequency simultaneously to minimize the external inductor and capacitor size, and thus achieving the minimum solution footprint. Applications Information Because of the high integration in the SY8009 IC, the application circuit based on this regulator IC is rather simple. Only input capacitor C IN , output capacitor C OUT , output inductor L and feedback resistors (R1 and R2) need to be selected for the targeted applications specifications. Feedback resistor dividers R1 and R2: Choose R1 and R2 to program the proper output voltage. To minimize the power consumption under light loads, it is desirable to choose large resistance values for both R1 and R2. A value of between 10k and 200k is highly recommended for R2. If R2=100k is chosen, then R1 can be calculated to be: 2OUT1 (V 0.6 V) RR 0.6V − ⋅= Input capacitor C IN With the maximum load current at 1.2A, the maximum ripple current through input capacitor is about 0.6Arms. A typical X7R or better grade ceramic capacitor with 6V rating and greater than 4.7uF capacitance can handle this ripple current well. To minimize the potential noise problem, place this ceramic capacitor really close to the IN and GND pins. Care should be taken to minimize the loop area formed by C IN , and IN/GND pins. Output capacitor C OUT The output capacitor is selected to handle the output ripple noise requirements. Both steady state ripple and transient requirements must be taken into consideration when selecting this capacitor. For the best performance, it is recommended to use X7R or better grade ceramic capacitor with 6V rating and greater than 4.7uF capacitance. Output inductor L: There are several considerations in choosing this inductor. 1) Choose the inductance to provide the desired ripple current. It is suggested to choose the ripple current to be about 40% of the maximum output current. The inductance is calculated as: 40%IF )/VV(1VL MAXOUT,SW MAXIN,OUTOUT where Fsw is the switching frequency and I OUT MAX is the maximum load current. The SY8009 regulator IC is quite tolerant of different ripple current amplitude. Consequently, the final choice of inductance can be slightly off the calculation value without significantly impacting the performance. 2) The saturation current rating of the inductor must be selected to be greater than the peak inductor current under full load conditions. OUT OUT IN MAX SAT MIN OUT MAX SW 3) The DCR of the inductor and the core loss at the switching frequency must be low enough to achieve the desired efficiency requirement. It is desirable to choose an inductor with DCR<50mΩ to achieve a good overall efficiency. Layout Design: The layout design of SY8009 regulator is relatively simple. For the best efficiency and minimum noise problems, we should place the following components close to the IC: C IN , L, R1 and R2. 1) It is desirable to maximize the PCB copper area connecting to GND pin to achieve the best thermal and noise performance. If the board space allowed, a ground plane is highly desirable.

AN_SY8009 AN_SY8009 Rev. 0.71 Silergy Corp. Confidential- Prepared for Internal Use Only 7 2) C IN must be close to Pins IN and GND. The loop area formed by C IN and GND must be minimized. 3) The PCB copper area associated with LX pin must be minimized to avoid the potential noise problem. 4) The components R1 and R2, and the trace connecting to the FB pin must NOT be adjacent to the LX net on the PCB layout to avoid the noise problem. 5) If the system chip interfacing with the EN pin has a high impedance state at shutdown mode and the IN pin is connected directly to a power source such as a LiIon battery, it is desirable to add a pull down 1MΩ resistor between the EN and GND pins to prevent the noise from falsely turning on the regulator at shutdown mode. Load Transient Considerations: The SY8009 regulator IC integrates the compensation components to achieve good stability and fast transient responses. In some applications, adding a 22pF ceramic cap in parallel with R1 may further speed up the load transient responses and is thus recommended for applications with large load transient step requirements.

AN_SY8009 AN_SY8009 Rev. 0.71 Silergy Corp. Confidential- Prepared for Internal Use Only 8 2.40 0.80 0.55

0.95 TYP

2.40 0.80 0.55 1.50 - 1.70 0.30 - 0.50 2.80 - 3.10 2.70 - 3.00 1.50 - 1.70 0.30 - 0.50 2.80 - 3.10 2.70 - 3.00 Recommended Pad Layout 0.1 - 0.15

0.25 REF

0.3 - 0.6 0.1 - 0.15 0.3 - 0.6 1.0 - 1.3 0.01 - 0.1

1.90 TYP

1.0 - 1.3 0.01 - 0.1 Notes: All dimensions are in millimeters. All dimensions don’t include mold flash & metal burr.

AN_SY8009 AN_SY8009 Rev. 0.71 Silergy Corp. Confidential- Prepared for Internal Use Only 9 0.95 2.40 1.90 0.60 1.00 0.95 2.40 1.90 0.60 1.00 2.30 - 2.50 2.50 - 3.00 0.25 - 0.40 Recommended Pad Layout 0.30 - 0.60 0.10 - 0.20 0.30 - 0.60 0.10 - 0.20 2.95 - 3.10 0.90 - 1.00 0.01 - 0.10 2.95 - 3.10 0.90 - 1.00 0.01 - 0.10 Notes: All dimensions are in millimeters. All dimensions don’t include mold flash & metal burr.