View RT9266BPE_4120904.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

RT9266B
Tiny Package, High Efficiency, Step-Up DC/DC Converter
General Description
The RT9266B is a compact, high efficiency, and low voltage step-up DC/DC converter with an Adaptive Current Mode PWM control loop, includes an error amplifier, ramp generator, comparator, switch pass element and driver in which providing a stable and high efficient operation over a wide range of load currents. It operates in stable waveforms without external compensation. The low start-up input voltage below 1V makes RT9266B suitable for 1 to 4 battery cells applications with a 500mA internal switch. The 550kHz high switching rate minimized the size of external components. Besides, the 25A low quiescent current together with high efficiency maintains long battery lifetime.
Features
1.0V Low Start-up Input Voltage at 1mA Load 25A Quiescent (Switch-off) Supply Current Zero Shutdown Mode Supply Current 90% Efficiency 550kHz Switching Frequency at 3.3V VDD Providing Flexibility for Using Internal and External Power Switches Small SOT-23-6 Package RoHS Compliant and 100% Lead (Pb)-Free
Applications
PDA DSC LCD Panel RF-Tags MP3 Portable Instrument Wireless Equipment
Ordering Information
RT9266B Package Type E : SOT-23-6 Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard)
Pin Configurations
(TOP VIEW)
FB 6 1 EN VDD 5 2 LX 4 3
Note : RichTek Pb-free and Green products are : RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. 100% matte tin (Sn) plating.
EXT GND
SOT-23-6
Marking Information
For marking information, contact our sales representative directly or through a RichTek distributor located in your area, otherwise visit our website for detail.
Note : There is no pin1 indicator on top mark for SOT-23-6 type, and pin 1 will be lower left pin when reading top mark from left to right.
DS9266B-09 March 2007
www.richtek.com 1
RT9266B
Typical Application Circuit
L1 VIN C3 10uF 3.3 to 10 uH D1 SS0520 VOUT 3.3V/5V R1 1.6M/3M C1 10uF
C2 1uF VDD EN EXT RT9266B GND LX FB R2 980k/1M
Figure 1. RT9266B Typical Application for Portable Instruments
L1 VIN C3 10uF 3.3 to 10 uH
D1 SS0520
VOUT 3.3V/5V
C2 1uF VDD EN LX Q1 N MOS R1 1.6M/3M C1 10uF R2 980k/1M
RT9266B EXT GND FB
Figure 2. RT9266B for Higher Current Applications
Test Circuit
I (VIN) VIN L1 C3 10uF 10uH
+
D1 SS0520 VOUT 3.3V/5V R1 1.6M/3M C4 100p C5 10uF
A
A I (VDD)
VDD EN EXT RT9266B GND LX FB
C2 1uF
R2 980k/1M
www.richtek.com 2
DS9266B-09 March 2007
RT9266B
Functional Pin Description
Pin Name Pin Function EN EXT GND LX VDD FB Chip Enable (Active High) Output Pin for Driving External NMOS Ground Pin for Switching Input Positive Power Pin of RT9266B Feedback Input Pin Internal Reference Voltage for the Error Amplifier is 1.25V.
Function Block Diagram
EXT VDD RT9266B LX1 FB 1.25V VDD R2 Shut Down EN Q3 N MOS
Over Temp. Detector
+
Loop Control Circuit
Q1 N MOS R1
GND
DS9266B-09 March 2007
www.richtek.com 3
RT9266B
Absolute Maximum Ratings
Supply Voltage ----------------------------------------------------------------------------------------------------- -0.3V to 7V LX Pin Switch Voltage -------------------------------------------------------------------------------------------- -0.3V to 6.5V Other I/O Pin Voltages ------------------------------------------------------------------------------------------- -0.3V to (VDD + 0.3V) LX Pin Switch Current -------------------------------------------------------------------------------------------- 2.5A EXT Pin Driver Current -------------------------------------------------------------------------------------------- 200mA Package Thermal Resistance SOT-23-6, JC ------------------------------------------------------------------------------------------------------ 145C/W Operating Junction Temperature ------------------------------------------------------------------------------- 125C Storage Temperature Range ------------------------------------------------------------------------------------ -65C to +150C
Electrical Characteristics
(VIN = 1.5V, VDD set to 3.3V, Load Current = 0, TA = 25C, unless otherwise specified)
Parameter Start-UP Voltage Operating VDD Range No Load Current I (VIN) Switch-off Current I (VDD) Shutdown Current I (VIN) Feedback Reference Voltage Switching Frequency Maximum Duty LX ON Resistance Current Limit Setting Current Limit Delay Time EXT ON Resistance to VDD EXT ON Resistance to GND Line Regulation (refer to VFB) Load Regulation (refer to VFB) EN Pin Trip Level Temperature Stability for Vout Thermal Shutdown Thermal Shutdown Hysterises TS
Symbol VST VDD INO LOAD ISWITCH OFF IOFF VREF FS DMAX
Test Conditions IL = 1mA VDD pin voltage VIN = 1.5V, VOUT = 3.3V VIN = 6V EN Pin = 0V, VIN = 4.5V Close Loop, VDD = 3.3V VDD = 3.3V VDD = 3.3V VDD = 3.3V
Min -2 ---1.225 ---------0.4 ----
Typ 0.98 -150 25 0.01 1.25 550 95 0.35 0.5 300 5 5 12 0.25 0.8 50 165 10
Max 1.05 6.5 --1 1.275 ---------1.2 ----
Units V V A A A V kHz % A ns mV/V mV/mA V ppm/C C C
ILIMIT
VDD = 3.3V VDD = 3.3V VDD = 3.3V VDD = 3.3V
VLINE VLOAD
VIN = 1.5 ~ 2.5V, IL = 50mA VIN = 2.5V, IL = 1 ~ 100mA VDD = 3.3V
TSD TSD
www.richtek.com 4
DS9266B-09 March 2007
RT9266B
Typical Operating Characteristics
Efficiency vs. Output Current
95 90 85
100
Efficiency vs. Output Current
VIN = 4.5V VIN = 4V VIN = 3.5V VIN = 3V VIN = 2.5V VIN = 2V VIN = 1.5V
Efficiency (%)
80 75 70 65
VIN = 1V
Efficiency (%)
VIN = 3V VIN = 2.5V VIN = 2V VIN = 1.5V
90
80
70
VOUT = 3.3V, TA = 25C
60 1 10 100 1000
60 1
VOUT = 5V, TA = 25C
10 100 1000
Output Current (mA)
Output Current ( mA)
Output Voltage vs. Output Current
3.36
Output Voltage vs. Output Current
5.1
5.05
VIN = 4.5V
Output Voltage (V)
VIN = 3V
Output Voltage (V)
3.32
5
VIN = 4V VIN = 3.5V
3.28
VIN = 2.5V VIN = 2V
4.95
VIN = 3V VIN = 1.5V
4.9
3.24
VIN = 1.5V VIN = 1V VOUT = 3.3V, TA = 25C
VIN = 2.5V VIN = 2V
VOUT = 5V, TA = 25C
4.85
100 1000
3.2 1 10
1
10
100
1000
Output Current (mA)
Output Current (mA)
Input Current vs. Input Voltage
350 300
800 700
Input Current vs. Input Voltage
Input Current (uA)
250 200 150 100 50
Input Current (uA)
VOUT = 3.3V @ no load
600 500 400 300 200 100
VOUT = 5V @ no load
0
0 1 1.5 2 2.5 3
1
2
3
4
5
Input Voltage (V)
DS9266B-09 March 2007
Input Voltage (V)
www.richtek.com 5
RT9266B
LX & Output Ripple LX & Output Ripple
LX (V)
Output Ripple (mV)
VIN = 1V, VOUT = 3.3V @ 10mA
Output Ripple (mV)
LX (V)
VIN = 1V, VOUT = 3.3V @ 50mA
Time (1us/Div)
Time (1us/Div)
LX & Output Ripple
LX & Output Ripple
LX (V)
Output Ripple (mV)
VIN = 1.5V, VOUT = 3.3V @ 10mA
Output Ripple (mV)
LX (V)
VIN = 1.5V, VOUT = 3.3V @ 100mA
Time (1us/Div)
Time (1us/Div)
LX & Output Ripple
LX & Output Ripple
LX (V)
Output Ripple (mV)
Output Ripple (mV)
LX (V)
VIN = 2V, VOUT = 3.3V @ 10mA
VIN = 2V, VOUT = 3.3V @ 100mA
Time (1us/Div)
Time (1us/Div)
www.richtek.com 6
DS9266B-09 March 2007
RT9266B
LX & Output Ripple LX & Output Ripple
LX (V)
Output Ripple (mV)
VIN = 2.5V, VOUT = 3.3V @ 10mA
Output Ripple (mV)
LX (V)
VIN = 2.5V, VOUT = 3.3V @ 100mA
Time (1us/Div)
Time (1us/Div)
LX & Output Ripple
LX & Output Ripple
LX (V)
Output Ripple (mV)
VIN = 3V, VOUT = 3.3V @ 10mA
Output Ripple (mV)
LX (V)
VIN = 3V, VOUT = 3.3V @ 100mA
Time (1us/Div)
Time (1us/Div)
LX & Output Ripple
LX & Output Ripple
LX (V)
Output Ripple (mV)
Output Ripple (mV)
LX (V)
VIN = 1.5V, VOUT = 5V @ 10mA
VIN = 1.5V, VOUT = 5V @ 80mA
Time (1us/Div)
Time (1us/Div)
DS9266B-09 March 2007
www.richtek.com 7
RT9266B
LX & Output Ripple LX & Output Ripple
LX (V)
Output Ripple (mV)
VIN = 2V, VOUT = 5V @ 10mA
Output Ripple (mV)
LX (V)
VIN = 2V, VOUT = 5V @ 100mA
Time (1us/Div)
Time (1us/Div)
LX & Output Ripple
LX & Output Ripple
LX (V)
Output Ripple (mV)
VIN = 2.5V, VOUT = 5V @ 10mA
Output Ripple (mV)
LX (V)
VIN = 2.5V, VOUT = 5V @ 100mA
Time (1us/Div)
Time (1us/Div)
LX & Output Ripple
LX & Output Ripple
LX (V)
Output Ripple (mV)
VIN = 3V, VOUT = 5V @ 10mA
Output Ripple (mV)
LX (V)
VIN = 3V, VOUT = 5V @ 100mA
Time (1us/Div)
Time (1us/Div)
www.richtek.com 8
DS9266B-09 March 2007
RT9266B
LX & Output Ripple LX & Output Ripple
LX (V)
Output Ripple (mV)
VIN = 3.5V, VOUT = 5V @ 10mA
Output Ripple (mV)
LX (V)
VIN = 3.5V, VOUT = 5V @ 100mA
Time (1us/Div)
Time (1us/Div)
LX & Output Ripple
LX & Output Ripple
LX (V)
Output Ripple (mV)
Output Ripple (mV)
LX (V)
VIN = 4V, VOUT = 5V @ 10mA
VIN = 4V, VOUT = 5V @ 100mA
Time (2.5us/Div)
Time (1us/Div)
LX & Output Ripple
LX & Output Ripple
LX (V)
Output Ripple (mV)
Output Ripple (mV)
LX (V)
VIN = 4.5V, VOUT = 5V @ 10mA
VIN = 4.5V, VOUT = 5V @ 100mA
Time (5us/Div)
Time (1us/Div)
DS9266B-09 March 2007
www.richtek.com 9
RT9266B
Load Transient Respones
Output Voltage (mV) Output Voltage (mV)
Load Transient Respones
Output Current (mA)
VIN = 1V, VOUT = 3.3V, IOUT = 10mA to 50mA
Output Current (mA)
VIN = 1.5V, VOUT = 3.3V, IOUT = 10mA to 100mA
Time (2.5ms/Div)
Time (2.5ms/Div)
Load Transient Respones
Output Voltage (mV) Output Voltage (mV)
Load Transient Respones
Output Current (mA)
VIN = 3V, VOUT = 3.3V, IOUT = 10mA to 100mA
Output Current (mA)
VIN = 3V, VOUT = 5V, IOUT = 10mA to 100mA
Time (2.5ms/Div)
Time (2.5ms/Div)
Load Transient Respones
Output Voltage (mV) Output Voltage (mV)
Load Transient Respones
Output Current (mA)
VIN = 3.5V, VOUT = 5V, IOUT = 10mA to 100mA
Output Current (mA)
VIN = 4.2V, VOUT = 5V, IOUT = 10mA to 100mA
Time (2.5ms/Div)
Time (2.5ms/Div)
www.richtek.com 10
DS9266B-09 March 2007
RT9266B
Switching Frequency vs. VDD Pin Voltage
700
Switching Frequency (kHz) 1
600 500 400 300 200 100 0 1 2 3 4 5 6
VDD = EN FB = GND TA = 25C
VDD Pin Voltage (V)
DS9266B-09 March 2007
www.richtek.com 11
RT9266B
Application Information
Output Voltage Setting Referring to application circuits, the output voltage of the switching regulator (VOUT) can be set with Equation (1).
VOUT1 = ( 1+ R1 R2 ) x 1.25V
Layout Guide A full GND plane without gap break. VDD to GND noise bypass - Short and wide connection for the 1mF MLCC capacitor between Pin5 and Pin3. VIN to GND noise bypass - Add a capacitor close to L1 inductor, when VIN is not an idea voltage source. Minimized FB node copper area and keep far away from noise sources. Minimized parasitic capacitance connecting to LX and EXT nodes, which may cause additional switching loss. Board Layout Example (2-Layer Board) (Refer to Application Circuit Figure 2 for the board)
(1)
Feedback Loop Design Referring to application circuits, The selection of R1 and R2 based on the trade-off between quiescent current consumption and interference immunity is stated below: Follow Equation (1). Higher R reduces the quiescent current (Path current = 1.25V/R2), however resistors beyond 5M are not recommended. Lower R gives better noise immunity, and is less sensitive to interference, layout parasitics, FB node leakage, and improper probing to FB pins.
VOUT1 R1 FB Pin _ Q + R2
Prober Parasitics
A proper value of feed forward capacitor parallel with R1 can improve the noise immunity of the feedback loops, especially in an improper layout. An empirical suggestion is around 0~33pF for feedback resistors of M, and 10nF~0.1F for feedback resistors of tens to hundreds k. For applications without standby or suspend modes, lower values of R1 and R2 are preferred. For applications concerning the current consumption in standby or suspend modes, the higher values of R1 and R2 are needed. Such "high impedance feedback loops" are sensitive to any interference, which require careful layout and avoid any interference, e.g. probing to FB pin.
- Top Layer -
- Bottom Layer -
www.richtek.com 12
DS9266B-09 March 2007
RT9266B
Outline Dimension
H D L C B
b A A1 e
Symbol A A1 B b C D e H L
Dimensions In Millimeters Min 0.889 0.000 1.397 0.250 2.591 2.692 0.838 0.080 0.300 Max 1.295 0.152 1.803 0.560 2.997 3.099 1.041 0.254 0.610
Dimensions In Inches Min 0.031 0.000 0.055 0.010 0.102 0.106 0.033 0.003 0.012 Max 0.051 0.006 0.071 0.022 0.118 0.122 0.041 0.010 0.024
SOT-23-6 Surface Mount Package
Richtek Technology Corporation
Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611
Richtek Technology Corporation
Taipei Office (Marketing) 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com
DS9266B-09 March 2007
www.richtek.com 13

▲Up To Search▲

Price & Availability of RT9266BPE

	To Download RT9266BPE Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .