MAX1763EEE Maxim Integrated Products, MAX1763EEE Datasheet - Page 13

• Manufacturer Part Number: MAX1763EEE
• Description: IC CONV DC/DC STEP UP LN 16QSOP
• Manufacturer: Maxim Integrated Products
• Type: Step-Up (Boost)r

Specifications of MAX1763EEE

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 3.3V, 2.5 ~ 5.5 V
• Current - Output: 1.5A
• Frequency - Switching: 1MHz
• Voltage - Input: 0.7 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Power - Output: 667mW
• Output Voltage: 3.3 V
• Output Current: 1.5 A
• Input Voltage: 0.7 V to 5.5 V
• Supply Current: 2.5 mA
• Switching Frequency: 1200 MHz
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Table 4. Component Selection Guide
resistance of the package from +115°C/W for QSOP to
+53°C/W for the TSSOP-EP.
At an ambient temperature of +70°C, continuous power
dissipation for the QSSOP package is 667mW, while
the TSSOP-EP can dissipate 1.5W. A first-order esti-
mate of power dissipation can be determined by calcu-
lating the output power delivered to the load (e.g., 3.3V
✕
ciency from the Typical Operating Characteristics
graphs (e.g., 87%). The estimated power dissipation in
the MAX1763 is then: (100% - %Efficiency)
Power. The example would have: 13%
allowing the QSOP package (667mW) to be used. For
higher ambient temperature, higher output power, or a
lower-efficiency operating point, the TSSOP-EP pack-
age (1.5W) may be necessary. For detailed package
mechanical information, see the package outline draw-
ings at the end of this data sheet.
The MAX1763’s high switching frequency allows the
use of a small 1.5µH surface-mount inductor. The cho-
sen inductor should generally have a saturation current
rating exceeding the N-channel switch current limit;
however, it is acceptable to bias the inductor current
into saturation by as much as 20% if a slight reduction
in efficiency is acceptable. Inductors rated for lower
peak current may be used if ISET is employed to
reduce the peak inductor current (see Setting the
Switch Current Limit and Soft-Start). For high efficiency,
choose an inductor with a high-frequency ferrite core
material to reduce core losses. To minimize radiated
noise, use a toroid or shielded inductor. See Table 4 for
suggested components and Table 5 for a list of compo-
nent suppliers. Connect the inductor from the battery to
the LX pins as close to the IC as possible.
For output voltages greater than 4V, an external
Schottky diode must be connected from LX to POUT, in
parallel with the on-chip synchronous rectifier (Figure
2). The diode should be rated for 0.5A. Representative
devices are Motorola MBR0520L, Nihon EP05Q03L, or
Coilcraft LPT3305
Sumida
1A = 3.3W). At the input voltage used, find the effi-
INDUCTORS
______________________________________________________________________________________
AVX TPS series
Kemet T510 series
Sanyo POSCAP series
Panasonic SP/CB
CAPACITORS
Inductor Selection
External Diode
1.5A, Low-Noise, 1MHz, Step-Up
✕
3.3W = 0.43W,
Motorola
MBR0520L
Nihon
EP10QY03
DIODES
✕
Output
generic 1N5817. This external diode is also recom-
mended for applications that must start with input volt-
ages at or below 1.8V. The Schottky diode carries
current during both startup and after the synchronous
rectifier turns off. Thus, its current rating only needs to
be 500mA even if the inductor current is higher.
Connect the diode as close to the IC as possible. Do
not use ordinary rectifier diodes; their slow switching
speeds and long reverse-recovery times render them
unacceptable. For circuits that do not require startup
with inputs below 1.8V, and have an output of 4V or
less, no external diode is needed.
Choose input and output capacitors that will service the
input and output peak currents with acceptable voltage
ripple. Choose input capacitors with working voltage
ratings over the maximum input voltage, and output
capacitors with working voltage ratings higher than the
output. A 220µF, low equivalent-series-resistance (ESR)
(less than 100mΩ) capacitor is recommended for most
applications. Alternatively, two 100µF capacitors in par-
allel will reduce the effective ESR for even better perfor-
mance.
The input capacitor reduces peak currents drawn from
the input source and also reduces input switching noise.
The input voltage source impedance determines the
required size of the input capacitor. When operating
directly from one or two NiMH cells placed close to the
MAX1763, use a single 47µF low-ESR input filter capaci-
tor. With higher impedance batteries, such as alkaline
and Li+, a higher value input capacitor may improve effi-
ciency.
Sanyo POSCAP, Panasonic SP/CB, and Kemet T510
are good low-ESR capacitors (Tables 4 and 5). Low-
ESR tantalum capacitors offer a good trade-off between
price and performance. Do not exceed the ripple cur-
rent ratings of tantalum capacitors. Avoid aluminum
Table 5. Component Suppliers
Note: Please indicate that you are using the MAX1763 when
contacting these component suppliers.
AVX
Coilcraft
Kemet
Motorola
Sumida
SUPPLIER
DC-DC Converter
Input and Output Capacitors
USA: 843-448-9411
USA: 847-639-6400
USA: 810-287-2536
USA: 408-629-4789
Japan: 81-45-474-7030
USA: 847-956-0666
Japan: 011-81-3-3667-3302
PHONE
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