SP7600EB Exar Corporation, SP7600EB Datasheet - Page 10

• Manufacturer Part Number: SP7600EB
• Description: EVAL BOARD FOR SP7600
• Manufacturer: Exar Corporation

Specifications of SP7600EB

• Current - Output / Channel: 2A
• Outputs And Type: 1, Non-Isolated
• Features: PWM Brightness control
• Voltage - Input: 4.5 ~ 29 V
• Utilized Ic / Part: SP7600
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Product: Display Modules
• Core Chip: SP7600
• No. Of Outputs: 1
• Output Current: 2A
• Output Voltage: 200mV
• Dimming Control Type: PWM
• Development Tool Type: Hardware - Eval/Demo Board
• Mcu Supported Families: SP7600
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Voltage - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 1016-1233

a string of series connected LEDs Vo equals
total Vf)
ΔI
30% of Io)
Inductor Isat and Irms must allow sufficient
safeguard over output current Io. As a rule of
thumb these parameters should be 50%
higher than Io. Where high efficiency is
required a low DCR inductor should be used.
I
Select the input capacitor for capacitanceand
ripple current rating. Use the capacitances
listed in the table 1 as a starting point and if
needed increase Cin.
Calculate the ripple current requirement from:
Where
Ceramic capacitors are recommended for input
filtering due to their low Equivalent Series
© 2009 Exar Corporation
NPUT CAPACITOR SELECTION
L
is inductor current ripple (nominally set to
0.71 to 1.2
D =
Equ.4:
I
<0.7
>1.2
O
(A)
Vin
Vo
Table 1: Cin Selection
Irip
=
Io
×
D
×
Cin (µF)
1 ( D
2 x 4.7
−
2.2
4.7
)
2
2
A
A
2
2
9
9
V
V
10/13
N
N
o
o
n
n
Resistance
inductance (ESL) and small form factor.
S
Select the Schottky D1 for Voltage rating VR
and current rating If. Recommended schottky
diode
applications is 30V and 40V respectively.
Current rating can be calculated from:
Note that in applications where duty cycle is
low,
percentage of converter losses. In order to
improve the efficiency in these applications
choose a Schottky that meets the calculated
current rating and has a lower Vf.
F
R2 is part of SP7600 loop compensation
network. Use a 30k R2 for Vin of 20V and
larger. Use R2 of 60K for Vin less than 20V.
C
This is the decoupling capacitor for the power
supply for the internal driver. Use a 0.1uF and
place as closely to VDR and SVIN pins as
possible.
-
-
S
S
EEDBACK RESISTOR
CHOTTKY RECTIFIER SELECTION
APACITOR
y
y
n
n
c
c
Schottky
.
.
voltage
B
B
Equ.5 :
u
u
C5
c
c
k
k
(ESR),
H
H
rating
losses
i
i
If
g
g
h
h
≥ 1
RFB
P
P
o
o
for
Equivalent
comprise
−
w
w
Vin
Vo
e
e
r
r
12V
×
L
L
Io
E
E
S
S
D
D
P
and
P
a
Rev. 2.0.0
D
D
7
7
r
r
Series
6
6
larger
i
i
v
v
0
0
24V
e
e
0
0
r
r