MAX1763EEE Maxim Integrated Products, MAX1763EEE Datasheet - Page 11

• 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 3. On/Off Logic Control
Figure 3. Using the Gain Block as a Power-OK Comparator
Figure 4. Using the Gain Block as a Linear Regulator from the
Boosted Output Voltage
within 0.2in (5mm) of the REF pin. REF can source up
to 50µA of external load current.
The MAX1763 gain block can function as a power-OK
comparator or can be used to build a linear regulator
R3
R4
0.22µF
ONA
0
0
1
1
TO V
R3
R4
REF
V
CLK/SEL
ONA
ONB
AIN
ISET
PGND
OUT
IN
MAX1763
OR
______________________________________________________________________________________
AIN
GND
POUT
OUT
AO
LX
FB
1.5µH
1.8V TO 5.5V
MAX1763
L1
ONB
V
IN
0
1
0
1
R5
4.7Ω
C2
1.0µF
R2
30k
R1
POUT
C1
47µF
AO
C4
220µF
1.5A, Low-Noise, 1MHz, Step-Up
R
20k
R6
150k
G
Gain Block
MAX1763
P
On
Off
On
On
POWER-OK
OUTPUT
SIGNAL
GROUND
POWER
GROUND
BOOST
OUTPUT
LINEAR-
REGULATED
OUTPUT
C
47µF
OUT
using an external P-channel MOSFET pass device. The
gain-block output is a single-stage transconductance
amplifier that drives an open-drain N-channel MOSFET.
The transconductance (G
stage is 10mS. The internal gain block amplifies the dif-
ference between AIN and the internal 0.938V reference.
To provide a power-OK signal, connect the gain-block
input, AIN, to an external resistor-divider (Figure 3). The
input bias current into AIN is less than 30nA, allowing
large-value divider resistors without sacrificing accura-
cy. Connect the resistor voltage-divider as close to the
IC as possible, within 0.2in (5mm) of AIN. Choose an
R4 value of 270kΩ or less, then calculate R3 using:
where V
Figures 4 and 5 show the gain block used in a linear-
regulator application. The output of an external P-chan-
nel pass element is compared to an internal 0.938V
reference. The difference is amplified and drives the
gate of the pass element. Use a logic-level PFET, such
as Fairchild’s NDS336P (R
linear-regulator output voltage is in regulation, the
MOSFET will not be full on; thus, the on-resistance will
not be important. However, if the linear regulator is used
Figure 5. Powering a Gain-Block Linear Regulator from the
Input Voltage
165k
100k
R3
R4
0.22µF
C3
AIN
V
IN
is 0.938V.
R3 = R4((V
DC-DC Converter
REF
CLK/SEL
ONB
ONA
AIN
ISET
PGND
MAX1763
AO
GND
POUT
OUT
LX
FB
1.5µH
TRIP
R
20k
DS(ON)
G
M
) of the entire gain-block
/ V
R5
4.7Ω
MBRO520L
C2
1µF
AIN
= 270mΩ). When the
) - 1)
C1
47µF
C4
220µF
3.3V
C
47µF
OUT
2.5V
11