MAX1674EUA+T Maxim Integrated Products, MAX1674EUA+T Datasheet - Page 12

• Manufacturer Part Number: MAX1674EUA+T
• Description: IC DC-DC CONV HI EFF 8-UMAX
• Manufacturer: Maxim Integrated Products
• Type: Step-Up (Boost)r

Specifications of MAX1674EUA+T

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 3.3V, 5V, Adj
• Current - Output: 420mA
• Frequency - Switching: 500kHz
• Voltage - Input: 0.7 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Power - Output: 330mW
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12
High-Efficiency, Low-Supply-Current,
Compact, Step-Up DC-DC Converters
Although not required, a Schottky diode (such as the
MBR0520) connected between LX and OUT allows
lower start-up voltages (Figure 10) and is recommend-
ed when operating at input voltages below 1.3V. Note
that adding this diode provides no significant efficiency
improvement.
Careful printed circuit layout is important for minimizing
ground bounce and noise. Keep the IC’s GND pin and
the ground leads of the input and output filter capaci-
tors less than 0.2in (5mm) apart. In addition, keep all
connections to the FB and LX pins as short as possi-
ble. In particular, when using external feedback resis-
tors, locate them as close to the FB as possible. To
maximize output power and efficiency and minimize
output ripple voltage, use a ground plane and solder
the IC’s GND directly to the ground plane.
______________________________________________________________________________________
PC Board Layout and Grounding
Optional External Rectifier
Figure 10. Adding a Schottky Diode for Low Input Voltage
Operation
TRANSISTOR COUNT: 751
R3
R4
0.1µF
200Ω
R1
BATT
(MAX1676)
LBI
REF
CLSEL
(MAX1676)
MAX1674
MAX1675
MAX1676
GND
Package Information
SHDN
OUT
LBO
LX
FB
Chip Information
47µF
R2
100k
0.1µF
V
IN
LOW-BATTERY
OUTPUT
22µH
MBR0520
47µF