Transcript
RT9266 Tiny Package, High Efficiency, Step-up DC/DC Converter General Description
Features
The RT9266 is a compact, high efficiency, and low voltage
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1.0V Low Start-up Input Voltage
step-up DC/DC converter with an Adaptive Current Mode
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High Supply Capability to Deliver 3.3V 100mA with 1 Alkaline Cell
PWM control loop, includes an error amplifier, ramp generator, comparator, switch pass element and driver
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17uA Quiescent (Switch-off) Supply Current
in which providing a stable and high efficient operation
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Zero Shutdown Mode Supply Current
over a wide range of load currents. It operates in stable
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90% Efficiency
waveforms without external compensation.
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450kHz Fixed Switching Frequency
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Providing Flexibility for Using Internal and External
The low start-up input voltage below 1V makes RT9266
Power Switches
suitable for 1 to 4 battery cells applications of providing up to 300mA output current. The 450kHz high switching rate minimized the size of external components. Besides, the 17uA low quiescent current together with high efficiency maintains long battery lifetime. The output voltage is set with two external resistors. Both internal 2A switch and driver for driving external power devices (NMOS or NPN) are provided.
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Small SOT-23-6 & SOT-89-5 Package
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RoHS Compliant and 100% Lead (Pb)-Free
Applications l
PDA
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DSC
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LCD Panel
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RF-Tags
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MP3
Ordering Information
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Portable Instrument
RT9266
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Wireless Equipment
Package Type E : SOT-23-6 X5 : SOT-89-5
Pin Configurations
Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard)
(TOP VIEW) GND
LX
5
4
FB VDD LX
Note : Richtek Pb-free and Green products are : }
RoHS compliant and compatible with the current require-
6
5
4
2
3
Suitable for use in SnPb or Pb-free soldering processes.
2
3
EN
VDD
FB
EN EXT GND
ments of IPC/JEDEC J-STD-020. }
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SOT-23-6
SOT-89-5
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.
DS9266-14 June 2009
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RT9266 Typical Application Circuit L1 +
VIN
D1
3.3 to 10 uH
C3 100uF
1N5819 VOUT 3.3V/5V
C2 1uF R1 1.6M/3M
VDD RT9266
LX
EXT
GND
FB
+
EN
C1 100uF
R2 980k/1M
Figure 1. RT9266 Typical Application for Portable Instruments
3.1V to 5V for 12V 2.8V to 5V for 9V VIN
L1
D1
+
4.7uH
C4 100uF
1N5819
RVDD 100 CVDD 1uF
EN
EXT
RT9266
LX
GND
FB
Q1 N MOS
12V/9V 300mA
R1 C3 0.1uF 860k/620k RM 0.22
R2 100k
C2 1uF
+
VDD
C1 100uF
Figure 2. RT9266 High Voltage Applications
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DS9266-14 June 2009
RT9266
L1 +
VIN
C3 100uF
D1
3.3 to 10 uH
VOUT 3.3V/5V
1N5819
C2 1uF VDD EN
LX
RT9266 EXT
+
GND
Q1 N MOS
R1 1.6M/3M
FB
C1 100uF
R2 980k/1M
Figure 3. RT9266 for Higher Current Applications
L1 VIN 3.3V/5V
R3 100
C2 1uF
4.7uH
C8 1uF
C3 10uF
C1 1uF Q1
EN
VDD
LX
RT9266
FB
GND
N MOS
C4 10uF C6 C7 1uF 0.1uF
VOUT2 +18V 10mA VOUT1 +9V 10mA
R1 620k
EXT R2 100k
C5 10uF
VOUT3 -9V 10mA
Figure 4. RT9266 for Multi-Output Applications
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RT9266 Test Circuit I (VIN)
L1
D1
10uH
+
A
VIN
C3 100uF
1N5819 VOUT 3.3V/5V +
C2 1uF
A I (VDD)
R1 1.6M/3M
VDD EN
RT9266
LX
EXT
GND
FB
C1 100uF
C4 102
C5 106
R2 980k/1M
Functional Pin Description Pin No.
Pin Name
Pin Function
SOT-23-6
SOT-89-5
1
1
EN
Chip Enable (Active High).
2
--
EXT
Output Pin for Driving External N-MOSFET.
3
5
GND
Ground.
4
4
LX
Pin for Switching.
5
2
VDD
Input Positive Power Pin of RT9266.
6
3
FB
Feedback Input Pin. Internal Reference Voltage for the Error Amplifier is 1.25V.
Function Block Diagram EXT RT9266
VDD
LX -
FB
+
1.25V
Loop Control Circuit
Q1 N MOS R1
VDD R2 Shut Down EN
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Q2 N MOS
Over Temp. Detector
GND
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RT9266 Absolute Maximum Ratings
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−0.3V to 7V LX Pin Switch Voltage ------------------------------------------------------------------------------------------ −0.3V to 7V Other I/O Pin Voltages ------------------------------------------------------------------------------------------ −0.3V to (VDD + 0.3V)
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LX Pin Switch Current ------------------------------------------------------------------------------------------- 2.5A
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EXT Pin Driver Current ------------------------------------------------------------------------------------------ 200mA
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Package Thermal Resistance
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Supply Voltage ---------------------------------------------------------------------------------------------------
SOT-23-6, θJC ----------------------------------------------------------------------------------------------------- 145 °C/W SOT-89-5, θJC ----------------------------------------------------------------------------------------------------- 45 °C/W l
Operating Junction Temperature ------------------------------------------------------------------------------ 125 °C
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Storage Temperature Range -----------------------------------------------------------------------------------
−65°C to +150°C
NOTE: Absolute Maximum ratings are threshold limit values that must not be exceeded even for an instant under any conditions. Moreover, such values for any two items must not be reached simultaneously. Operation above these absolute maximum ratings may cause degradation or permanent damage to the device. These are stress ratings only and do not necessarily imply functional operation below these limits
Electrical Characteristics (VIN = 1.5V, VDD set to 3.3V, Load Current = 0, T A = 25° C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
Start-UP Voltage
VST
IL = 1mA
--
0.98
1.05
V
Operating VDD Range
VDD
VDD pin voltage
2
--
6
V
Shutdown Current I (VIN)
IOFF
EN Pin = 0V, VIN = 4.5V
--
0.01
1
µA
Switch-off Current I (VDD)
ISWITCH OFF VIN = 6V
--
17
25
µA
Continuous Switching Current
ISWITCH
0.4
0.55
0.7
mA
--
µA
VIN = EN = 3.3V, VFB = GND
*
No Load Current I (VIN)
INO LOAD
VIN = 1.5V, VOUT = 3.3V
--
75
Feedback Reference Voltage
VREF
Close Loop, VDD = 3.3V
1.225
1.25
1.275
V
Switching Frequency
FS
VDD = 3.3V
425
500
575
kHz
Maximum Duty
DMAX
VDD = 3.3V
85
95
--
%
VDD = 3.3V
--
0.3
1.1
LX ON Resistance Current Limit Setting
**
Ω
VDD = 3.3V
1.6
2
2.6
A
EXT ON Resistance to VDD
VDD = 3.3V
--
5
8.5
Ω
EXT ON Resistance to GND
VDD = 3.3V
--
5
8.5
Ω
VIN = 3.5 ~ 6V, IL = 1mA
--
1.5
10
mV/V
--
mV/mA
Line Regulation Load Regulation
ILIMIT
∆VLINE ∆VLOAD
EN Pin Trip Level
VIN = 2.5V, IL = 1 ~ 100mA VDD = 3.3V
--
0.25
***
0.4
0.8
1.2
V
Temperature Stability for Vout
TS
--
50
--
ppm/°C
Thermal Shutdown Hysterises
∆TSD
--
10
--
°C
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RT9266 Note : * No Load Current is highly dependent on practical system design and component selection that cannot be covered by production testing. Typical No Load Current is verified by typical application circuit with recommended components. No Load Current performance is guaranteed by Switch Off Current and Continuous Switching Current. ** Current Limit is guaranteed by design at T A = 25°C. ***Load Regulation is not tested at production due to practical instrument limitation. Load Regulation performance is dominantly dependent on DC loop gain and LX ON Resistance that are guaranteed by “ Line Regulation ” and “ LX ON Resistance” tests in production.
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DS9266-14 June 2009
RT9266 Typical Operating Characteristics (Refer to Test Circuit)
Efficiency vs. Output Current
Efficiency vs. Output Current 95
95
VOUT = 5V, TA = 25°C
VOUT = 3.3V, TA = 25°C 90
VIN = VIN = VIN = VIN = VIN =
85
80
Efficiency (%)
Efficiency (%)
90
4.0V 3.5V 3.0V 2.5V 2.0V
75
VIN = 3.0V
85
VIN = 2.5V 80
VIN = 2.0V
75
VIN = 1.5V
VIN = 1.5V
VIN = 1.0V 70
70 000
001
010
100
0.1
1000
1
Input Current I(VDD) vs. Output Current
1000
21
VIN = 3V, VOUT = 5V
VOUT = 5V @ no load 20
Input Current ( µ A)
200
Input Current ( µ A)
100
Input Current I(VDD) vs. Input Voltage
250
150
100
50
19 18 17 16
0
15 0.01
0.1
1
10
100
1000
2.5
3.0
3.5
Output Current (mA)
4.0
4.5
5.0
Input Voltage (V)
Supply Current I(VIN) vs. Input Voltage
Supply Current I(VIN) vs. Input Voltage
180
90
VOUT = 5V @ no load
VOUT = 3.3V @ no load 80
150
Supply Current ( µA)
Supply Current ( µ A) 1
10
Output Current (mA)
Output Current (mA)
120 90 60
70 60 50 40
30
30
0 1.5
2.0
2.5
3.0
3.5
Input Voltage (V) DS9266-14 June 2009
4.0
4.5
1.5
2
2.5
3
3.5
Input Voltage (V) www.richtek.com 7
RT9266 Switching SwichtingFrequency Frequencyvs. vs. VDD VDD Pin PinVoltage Voltage
Start Up Voltage vs. Output Current 1.6
VIN = 2.4V to 2.8V 500
400
300
VOUT = 3.3V
1.4
VIN = 3V to 5.6V
Start Up Voltage (V)
Switching Rate Frequency (KHz). Switching Frequency (kHz)
600
VIN = 1.2V to 2.2V
1.2 1.0 0.8 0.6 0.4
200 0.2
(In C.R. mode) 0.0
100 0
1
2
3
4
5
0
6
30
60
90
120
150
VDD Pin Voltage (V)
Output Current (mA)
LX & Output Ripple
LX & Output Ripple
210
VIN = 1V, VOUT = 3.3V @ 10mA
VIN = 1V, VOUT = 3.3V @ 100mA
Output Ripple
Output Ripple
LX
LX
180
Time (1µs/Div)
Time (1µs/Div)
LX & Output Ripple
LX & Output Ripple
LX Time (1µs/Div)
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VIN = 2V, VOUT = 3.3V @ 10mA
Output Ripple
Output Ripple
LX
VIN = 2V, VOUT = 3.3V @ 200mA
Time (1µs/Div)
DS9266-14 June 2009
RT9266 LX & Output Ripple
LX & Output Ripple VIN = 3V, VOUT = 3.3V @ 10mA
Output Ripple
Output Ripple
LX
LX
VIN = 3V, VOUT = 3.3V @ 200mA
Time (1µs/Div)
Time (1µs/Div)
LX & Output Ripple
LX & Output Ripple
LX
VIN = 2V, VOUT = 5V @ 20mA
Output Ripple
Output Ripple
LX
VIN = 2V, VOUT = 5V @ 200mA
Time (1µs/Div)
Time (1µs/Div)
LX & Output Ripple
LX & Output Ripple
LX Time (1µs/Div)
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VIN = 3V, VOUT = 5V @ 20mA
Output Ripple
Output Ripple
LX
VIN = 3V, VOUT = 5V @ 200mA
Time (1µs/Div)
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RT9266 LX & Output Ripple
LX & Output Ripple
LX
VIN = 4.5V, VOUT = 5V @ 20mA
Output Ripple
Output Ripple
LX
VIN = 4.5V, VOUT = 5V @ 200mA
Time (1µs/Div)
Time (1µs/Div)
Transient Response
VIN = 3V, VOUT = 3.3V
IOUT = 10mA
IOUT = 10mA
200mA
Output Transient Voltage
VIN = 2V, VOUT = 3.3V
Output Transient Voltage
200mA
Time (50µs/Div)
Time (50µs/Div)
Transient Response
Transient Response
VIN = 3V, VOUT = 5V
VIN = 4.5V, VOUT = 5V
IOUT = 10mA
IOUT = 10mA
200mA
Time (50µs/Div)
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Output Transient Voltage
Output Transient Voltage
Transient Response
200mA
Time (50µs/Div)
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RT9266 Output Voltage vs. Temperature
Output Voltage vs. Temperature 5
3.34
VIN = 3V, VOUT = 5V, IOUT = 100mA
VIN = 1.8V, VOUT = 3.3V, IOUT = 100mA 4.98
Output Voltage(V)
Output Voltage(V)
3.32 3.3 3.28 3.26 3.24 3.22
4.96 4.94 4.92 4.9 4.88 4.86 4.84
3.2 -40
-10
20
50
80
Temperature (°C)
DS9266-14 June 2009
110
140
-40
-10
20
50
80
110
140
Temperature (°C)
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RT9266 Application Information Output Voltage Setting
Layout Guide
Referring to Typical Application Circuits, the output voltage
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A full GND plane without gap break.
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VDD to GND noise bypass − Short and wide connection
of the switching regulator (VOUT) can be set with Equation (1).
for the 1µF MLCC capacitor between Pin5 and Pin3. VOUT = ( 1+
R1 R2
) × 1.25V
(1)
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VIN to GND noise bypass − Add a capacitor close to L1 inductor, when VIN is not an idea voltage source.
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Feedback Loop Design
from noise sources.
Referring to Typical Application Circuits. The selection of R1 and R2 based on the trade-off between quiescent current consumption and interference immunity is stated below:
Minimized FB node copper area and keep far away
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Minimized parasitic capacitance connecting to LX and EXT nodes, which may cause additional switching loss.
Board Layout Example (2-Layer Board)
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Follow Equation (1)
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Higher R reduces the quiescent current (Path current
(Refer to Typical Application Circuits Figure 2 for the board)
= 1.25V/R2), however resistors beyond 5MΩ are not recommended. l
Lower R gives better noise immunity, and is less sensitive to interference, layout parasitics, FB node leakage, and improper probing to FB pins. VOUT
Prober Parasitics
R1 FB Pin
_ Q + l
R2
A proper value of feed forward capacitor parallel with
- Top Layer -
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 MΩ, and 10nF~0.1µF for feedback resistors of tens to hundreds kΩ. 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. - Bottom Layer www.richtek.com 12
DS9266-14 June 2009
RT9266 Outline Dimension
H D L C
B
b A A1 e
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
0.889
1.295
0.031
0.051
A1
0.000
0.152
0.000
0.006
B
1.397
1.803
0.055
0.071
b
0.250
0.560
0.010
0.022
C
2.591
2.997
0.102
0.118
D
2.692
3.099
0.106
0.122
e
0.838
1.041
0.033
0.041
H
0.080
0.254
0.003
0.010
L
0.300
0.610
0.012
0.024
SOT-23-6 Surface Mount Package
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RT9266 D D1 b1
A
C
B
C1 e
e
H
A
b
Symbol
b1
b
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
1.397
1.600
0.055
0.063
b
0.356
0.508
0.014
0.020
B
2.388
2.591
0.094
0.102
b1
0.406
0.533
0.016
0.021
C
3.937
4.242
0.155
0.167
C1
0.787
1.194
0.031
0.047
D
4.394
4.597
0.173
0.181
D1
1.397
1.702
0.055
0.067
e
1.397
1.600
0.055
0.063
H
0.356
0.432
0.014
0.017
5-Lead SOT-89 Surface Mount Package
Richtek Technology Corporation
Richtek Technology Corporation
Headquarter
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
8F, No. 137, Lane 235, Paochiao Road, Hsintien City
Hsinchu, Taiwan, R.O.C.
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)89191466 Fax: (8862)89191465 Email:
[email protected]
Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek 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 Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek.
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DS9266-14 June 2009
