ISL97702IRZ-T7 Intersil, ISL97702IRZ-T7 Datasheet - Page 11

• Manufacturer Part Number: ISL97702IRZ-T7
• Description: IC BOOST REG DUAL FEEDBACK 10DFN
• Manufacturer: Intersil
• Type: Step-Up (Boost)r

Specifications of ISL97702IRZ-T7

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 2
• Voltage - Output: Adj to 28V
• Current - Output: 130mA
• Frequency - Switching: 1MHz
• Voltage - Input: 2.3 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-DFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -

Typical Application
Typical applications are passive- or active-matrix organic
light emitting diode displays (PMOLED, AMOLED) in
handheld devices. Applications with low power or screen
saver/ reduced brightness modes are also directly
supported.
Motivation: In the low power mode the OLED display
brightness (~pixel current) is reduced so that the display
drivers can operate with equally reduced power. Usually the
supply voltage is kept at the same level, although the pixel
voltage drops by several volts when the pixel current levels
are reduced. Here a further power reduction can be
achieved if the supply voltage for the display drivers is
reduced according to the pixel diode characteristic.
The ISL97702 allows selection between a nominal and a
reduced output voltage level in order to supply more
effectively OLED display drivers.
Components Selection
The input capacitance is normally 10µf~15µF and the output
capacitor is 3.3µf to 6.6µF. X5R or X7R type of ceramic
capacitor with correct voltage rating is recommended. The
output capacitor value will affect the output voltage ripple.
Higher value of the output capacitor, lower ripple of the
output voltage.
When choosing an inductor, make sure the inductor can
handle the average and peak currents given by following
formulas (80% efficiency assumed):
I
LAVG
J2
GND_IN
J1
VDD_IN
J4
NSYNC
=
I
--------------------------------- -
OUT
VDD
0.8 V
JP3
⋅
⋅
V
OUT
IN
100n
C1
VDD
11
C2
10µ
4.7µ/10V
C9
FIGURE 20. ISL97702 APPLICATION BOARD
1
2
3
4
5
U1
GND
VDDOUT
VDD
NSYNC
FB0
(EQ. 1)
ISL97702
6.8µH
L1
ISL97702
VOUT
NEN
SEL
FB1
LX 10
9
8
7
6
Where:
• ∆I
• L inductance in H
• f
Optimal combination of the boost inductor L and the output
capacitor Cout are listed in table:
Recommended Inductor and Ceramic capacitor
manufactures are listed in the following table:
I
∆I
Sumida: www.sumida.com
TDK:
Toko:
LPK
L
OSC
INDUCTOR (µH)
=
L
=
390K
is the peak-to-peak inductor current ripple in Amperes
V
-------------------------------------------------- -
39K
I
R6
IN
L V
R1
switching frequency, typically 1.0MHz
LAVG
INDUCTOR
⋅
www.tdk.co.jp
www.tokoam.com
4.7
6.8
⋅
10
15
(
OUT
V
OUT
+
1
-- -
2
⋅
⋅
f
R4
OPEN
R2
OPEN
C3
OPEN
C4
OPEN
–
∆I
OSC
V
L
IN
)
26.1K
R5
Taiyo Yuden: www.t-yuden.com
AVX:
Murata:
MIN
C8
100n
2.2
3.3
4.7
6.8
3.3µF/50V
VDD
R3
OPEN
C5
OPEN
CAPACITOR (µF)
J2
CERAMIC CAPACITOR
C7
2
VDD
J1
www.avxcorp.com
www.murata.com
2
C6
1nF/50V
October 13, 2005
MAX
J7
VOUT
J3
GND_OUT
J6
NEN
J5
SEL
10
10
10
10
FN7462.0
(EQ. 2)
(EQ. 3)