MAX1709ESE+ Maxim Integrated Products, MAX1709ESE+ Datasheet - Page 10

• Manufacturer Part Number: MAX1709ESE+
• Description: IC DC/DC CONV STEP-UP 4A 16-SOIC
• Manufacturer: Maxim Integrated Products
• Type: Step-Up (Boost)r

Specifications of MAX1709ESE+

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 3.3V, 5V, Adj
• Current - Output: 4A
• Frequency - Switching: 600kHz
• Voltage - Input: 0.7 ~ 5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Power - Output: 1.3W
• Output Voltage: 3.26 V to 5.17 V
• Input Voltage: 0.7 V to 5 V
• Switching Frequency: 350 KHz
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4A, Low-Noise, High-Frequency,
Step-Up DC-DC Converter
from its nominal value (see Electrical Characteristics ). A
resistor (R1 in Figure 1) between SS/LIM and ground
reduces the current limit as follows:
where I
I
Characteristics .
The MAX1709’s high switching frequency allows the
use of a small-size inductor. Use a 1.0µH inductor for
600kHz operation. If the MAX1709 will be synchronized
Table 3. Component Selection Guide
Table 4. Component Suppliers
Figure 3. Simplified PWM Controller Functional Diagram
10
(LIMITED TO 100mV)
LIM
Coilcraft
Coiltronics
Motorola
Panasonic
STM-
Microelectronics
Surface mount
SUPPLIER
______________________________________________________________________________________
OSCILLATOR
is the current limit value from the Electrical
PRODUCTION
SLOPE
COMP
1
SS/LIM
R
12.5
REF
1
is the desired current limit in amperes, and
FB
=
312 5
.
k
Ω
847-639-6400
561-241-7876
602-303-5454
714-373-7939
617-259-0300
PHONE
×
Inductor Selection (L1)
I
Coilcraft DO3316P-102HC
Coiltronics UP2B-1R0
LIM
Design Procedure
I
1
R
S
(
R
1
Q
INDUCTORS
≤
312 5
847-639-1489
561-241-9339
602-994-6430
714-373-7183
617-259-9442
.
11mΩ
k
Ω
FAX
)
N
PGND
LX
Panasonic EEFUE0J151R
Sanyo 6TPC100M
at a different frequency, scale the inductor value with
the inverse of frequency (L
The PWM design tolerates inductor values within ±25%
of this calculated value, so choose the closest standard
inductor value. For example, use 1.5µH for 350kHz and
0.68µH for 1MHz.
Inductors with a ferrite core or equivalent are recom-
mended; powder iron cores are not recommended for
use at high switching frequencies. Ensure the induc-
tor’s saturation rating (the current at which the core
begins to saturate and inductance falls) exceeds the
internal current limit. Note that this current may be
reduced through SS/LIM if less than the MAX1709’s full
load current is needed (see Electrical Characteristics
for ratings). For highest efficiency, use a coil with low
DC resistance, preferably under 10mΩ. To minimize
radiated noise, use a toroid, pot core, or shielded
inductor. See Tables 3 and 4 for a list of recommended
components and component suppliers. To calculate the
maximum output current (in amperes), use the following
equation:
where:
V
Figure 4. Adjustable Output Voltage
IN
CAPACITORS
= input voltage
I
OUT MAX
(
)
MAX1709
=
KEEP SHORT
D I
'
⎛
⎜
⎝
LX
FB
LIM
V
−
Motorola MBRD1035CTL
STM-Microelectronics
STPS8L30B
IN
1
D
= 1µH
R3
'
⎛
⎜
⎝
R4
V
OUT

DIODES
2
+
600kHz / f
× ƒ ×
V
D
V
OUT
L
−
1
V
IN
SYNC
⎞
⎟
⎠
⎞
⎟
⎠
).