ETC CR-F33T

CR-F33T
Preliminary Specification
PFM STEP-UP
DC/DC CONVERTER
TM
BLOCK DIAGRAM
GENERAL DESCRIPTION
The CR-F33T is a PFM step-up DC/DC
converter IC and has a high efficiency.
These devices consist of a bandgap, a
comparator, an oscillator, a driver, and a
high current output switch.
The CR-F33T provides a higher fixed
voltage from the smaller input voltage.
The CR-F33T is used for single- or
dual-cell battery operation.
VDD
LX
Bandgap
Digital
Control
FB
VSSA
Clock
Select
150KHz
OSC
EN
VSS
FEATURES
PIN CONFIGURATION
z
z
z
z
Low Voltage Operation Possible
Low Supply Current
Small Number of External
Components
Internal Power Switch
SOP-8
(Top View)
APPLICATIONS
z
z
z
z
8 LX
VDD 1
FB 2
7 VSSA
EN 3
6 VSS
NC 4
5 NC
SOT-89-3
Battery-Powered Instruments
Hand-Held Instruments
Hand-Held Communication
Instruments
Cameras
(Top View)
1
3
2
VSS VDD LX
ORDERING INFORMATION
CR-FXXX
Step-up
1
Package
P: SOP-8
T: SOT-89-3
Output Voltage
33 : 3.3V
CR-F33T
Preliminary Specification
PFM STEP-UP
DC/DC CONVERTER
TM
PIN DESCRIPTION
Pin No.
Pin Name
Pin Function
1
VDD
2
FB
The pin of feedback voltage
3
EN
Chip enable pin
4
NC
No internal connection to this pin
5
NC
No internal connection to this pin
6
VSS
Ground pin
7
VSSA
Ground pin
8
LX
Output voltage pin and also power supply pin for
the device
Switch pin, connected to inductor/diode
STEP-UP CONVERTER APPLICATION
1N5819
1N5819
VDD
FB
EN
100uF
220uH
220uH
VDD
VIN 100uF
CR-F33-P
CR-F33-T
LX
LX
VSSA
VSS
VSS
Absolute Maximum Ratings
Supply Voltage-------------------------------------------------------------- - 0.3V to 7V
Input Voltage---------------------------------------------------------------- - 0.3V to VDD+0.3
Operating Temperature Range--------------------------------------------- 0 o C to 50 o C
Storage Temperature Range----------------------------------------------- - 40 o C to 150 o C
2
VIN
CR-F33T
Preliminary Specification
PFM STEP-UP
DC/DC CONVERTER
TM
Electrical Characteristics
Parameter
Symbol
Test Conditions
Min.
Start-Up Voltage
VST
Iload = 1mA
Holding Voltage
VHold
Iload = 1mA
0.45
Input Voltage
VIN
No Load
1
Output Voltage
VDD
Typ. Max. Units
0.9
1
V
V
3
3.5
V
3.3
3.6
V
8
14
μA
2
μA
No-Load Input Current
IIN
No Load
Standby Current
ISB
VEN = 0
Input Low Voltage
VIL
Enable/Disable Pin
0
0.4
V
Input High Voltage
VIH
Enable/Disable Pin
1
VDD
V
Oscillator Frequency
Fosc
Efficiency
η
VIN = 1.5V, Iload = 10mA
150
KHz
83
%
OPERATION OF STEP-UP CONVERTER
A step-up converter diagram is illustrated below. In the diagram, the converter can
generate a fixed, higher voltage from a lower one. When SW stays ON, IL1 flows
through L, and the converter converts the electric energy into the magnetic one and
stores it in L, in which Imax is proportional to ton; when SW lies OFF, Shottky diode is
forced to be ON, while the energy stored in inductor L be discharged into capacitor,
thereby charging the output voltage to a value expected.
IL
ILmax
IL2
L
Iout
D
+
+
IL1
VIN
--
SW
CL
Vout
--
3
ILmin
t
ton
toff
T=1/fosc
CR-F33T
Preliminary Specification
PFM STEP-UP
DC/DC CONVERTER
TM
TYPICAL PERFORMANCE CHARACTERISTICS
‹
L=47uH; C=100uF
4
90
Vin=3V
80
Vin=3V
70
Vin=2.5V
Vin=2.5V
3
Vin=1.2V
Vin=1.2V
Vin=2V
E fficiency (% )
Efficiency (% )
Vin=1.5V
50
40
Vin=2V
Vin=1.5V
60
2
30
1
20
10
0
0
0
10
20
30
40
50
60
70
80
90
0
100
10
20
30
40
‹
50
70
80
90
100
L=100uH; C=100uF
4
90
80
Vin=3V
70
Vin=3V
Vin=2.5V
Vin=1.2V
Vin=2.5V
3
Vin=2V
Vin=2V
Vin=1.5V
60
Vin=1.2V
Efficiency (%)
Efficiency (%)
60
Iload (mA)
Iload (mA)
Vin=1.5v
50
40
2
30
1
20
10
0
0
0
10
20
30
40
50
60
70
80
90
100
Iload (mA)
0
10
20
30
40
50
Iload (mA)
4
60
70
80
90
100
CR-F33T
Preliminary Specification
PFM STEP-UP
DC/DC CONVERTER
TM
‹
L=150uH; C=100uF
100
4
90
Vin=3V
80
Vin=1.2V
Vin=3V
60
Vin=2.5V
Vin=2V
Efficiency (%)
Efficiency (%)
3
Vin=1.2V
70
Vin=1.5V
50
40
Vin=2V
Vin=1.5V
Vin=2.5V
2
30
1
20
10
0
0
0
10
20
30
40
50
60
70
80
90
0
100
10
20
30
40
‹
50
60
70
80
90
100
90
100
Iload (mA)
Iload(mA)
L=220uH; C=100uF
4
90
80
Vin=3V
Vin=3V
70
Vin=1.2V
3
Vin=1.5V
Vin=1.5V
Vin=2V
50
Vin=2V
Vin=2.5V
Vin=1.2V
Vin=2.5V
E fficiency (% )
E fficiency (% )
60
40
2
30
1
20
10
0
0
0
10
20
30
40
50
60
70
80
90
100
Iload (mA)
0
10
20
30
40
50
Iload (mA)
5
60
70
80
Preliminary Specification
CR-F33T
PFM STEP-UP
DC/DC CONVERTER
TM
LX Pin Waveform & VDD
LX Pin Waveform & VDD
VDD
VDD
[email protected]=15mA
[email protected]=15mA
LX
LX
5us/Div
5us/Div
LX Pin Waveform & VDD
LX Pin Waveform & VDD
VDD
VDD
[email protected]=15mA
[email protected]=15mA
LX
LX
5us/Div
LX Pin Waveform & VDD
5us/Div
VDD
[email protected]=15mA
LX
5us/Div
6
CR-F33T
Preliminary Specification
PFM STEP-UP
DC/DC CONVERTER
TM
The magnitude of inductor will influence the performance of DC/DC converter. The
following table guides users to select the suitable magnitude of inductor for single- or
dual-cell battery operation when the output terminal connects to different current load.
Consequently, users can obtain a cell battery with longer life.
Current Load (mA)
1-cell battery
2-cell battery
Iload < 10
220uH
220uH
10 < Iload < 20
150uH
220uH
20 < Iload < 30
47uH
220uH
30 < Iload < 40
47uH
150uH
40 < Iload < 50
47uH
150uH
50 < Iload < 60
/
100uH
70 < Iload < 80
/
47uH
80 < Iload < 90
/
47uH
90 < Iload < 100
/
47uH
7
Preliminary Specification
CR-F33T
PFM STEP-UP
DC/DC CONVERTER
TM
PACKAGE INFORMATION
8
Preliminary Specification
CR-F33T
PFM STEP-UP
DC/DC CONVERTER
TM
9
˅
˘ˡ
˞˦ˈˋˈˉ˔ˢʳʳˣ˴̇̇˸̅́ʳ˗˼˴˺̅˴̀
˩˦˦
ˆ
˩˗˗
ˈ
˄
˩˦˦˔
ˇ
ˉ
˙˕
ˈˋˈˉˢ
˟ˢ˚ˢ
ˠ˴˼́ʳʳˣ˴̇̇˸̅́ʳʳ˦˼̍˸ʳʳˍʳʳʳˉ˃˅ˁ˃˃˃ʳͪʳʳˉ˄˃ˁ˃˃˃ʳӴ̀
˗˴̇˸ʳʳˍʳʳ˅˃˃ˇˁ˃˄ˁ˄ˈ
˥˸̀˴̅˾ʳʳˍʳʳ
˜˖ʳ̆̈˵̆̇̅˴̇˸ʳ˶̂́́˸˶̇ʳ̇̂ʳʳʳϭʳ˩˦˦˂˚ˡ˗ʳʳʳϭʳ˩˗˗ʳʳʳ̂̅ʳʳʳϭʳ˙˿̂˴̇˼́˺
˟˫
˄ˁʳ˦̇˸̃ˀ̈̃ʳ˶̂́̉˸̅̇˸̅ʳ˴̃̃˿˼˶˴̇˼̂́
1N5819
220uH
VDD
FB
EN
100uF
˅ˁʳ˕̂́˷˼́˺ʳ˗˼˴˺̅˴̀
VIN
CR-F33-P
LX
VSSA
VSS
ˆˁʳˣ˖˕ʳ˿˴̌̂̈̇ʳ˹̂̅ʳ̅˸˹˸̅˸́˶˸ʳ̂́˿̌