MAX771ESA+ Maxim Integrated Products, MAX771ESA+ Datasheet - Page 10

• Manufacturer Part Number: MAX771ESA+
• Description: IC CNTRLR DC-DC 8-SOIC
• Manufacturer: Maxim Integrated Products
• Type: Step-Up (Boost)r

Specifications of MAX771ESA+

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 12V, Adj
• Current - Output: 1A
• Frequency - Switching: 300kHz
• Voltage - Input: 2 ~ 16.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Power - Output: 471mW
• Output Voltage: 12 V or 3 V (Min)
• Output Current: 1 A (Max)
• Input Voltage: 2 V to 16.5 V
• Supply Current: 110 uA
• Switching Frequency: 300 KHz
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

frequencies (up to 300kHz), allowing the use of tiny
external components.
As with traditional PFM converters, the power transistor
is not turned on until the voltage comparator senses
that the output is out of regulation. However, unlike tra-
ditional PFM converters, the MAX770–MAX773 switch
using the combination of a peak current limit and a pair
of one-shots that set the maximum on-time (16µs) and
5V/12V/15V or Adjustable, High-Efficiency,
Low I
Figure 2a. 5V Preset Output, Bootstrapped
Figure 2c. 12V Output, Non-Bootstrapped
10
0.1 F
0.1 F
V
R2 = (R1)
V
68 F
IN
REF
C3
______________________________________________________________________________________
C3
C1
= 5V
= 1.5V
5
4
3
6
5
4
6
(
C2
0.1 F
V
V
OUT
REF
REF
SHDN
FB
AGND
REF
SHDN
AGND
Q
-1
C2
0.1 F
)
, Step-Up DC-DC Controllers
MAX770
MAX770
MAX771
MAX772
GND
GND
V+
V+
2
7
2
7
EXT
EXT
CS
CS
FB
1
8
1
8
3
22 H
22 H
V
L1
IN
L1
= 3V
MTP3055EL
N
N
R
100m
R
75m
1N5817
SENSE
1N5817
SENSE
100 F
D1
D1
18k
R1
C1
C4
200 F
127k
R2
C4
300 F
V
V
OUT
@ 0.5A
OUT
@ 1A
= 12V
= 5V
minimum off-time (2.3µs); there is no oscillator. Once
off, the minimum off-time one-shot holds the switch
off for 2.3µs. After this minimum time, the switch either
1) stays off if the output is in regulation, or 2) turns on
again if the output is out of regulation.
The control circuitry allows the ICs to operate in contin-
uous-conduction mode (CCM) while maintaining high
efficiency with heavy loads. When the power switch is
Figure 2b. 12V Preset Output, Bootstrapped
Figure 2d. 9V Output, Bootstrapped
0.1 F
0.1 F
R2 = (R1)
V
C3
REF
C3
= 1.5V
5
4
3
6
(
5
4
6
C2
0.1 F
C2
0.1 F
V
V
REF
SHDN
FB
AGND
OUT
REF
REF
SHDN
AGND
-1
MAX771
)
MAX770
MAX771
MAX772
GND
V+
GND
V+
2
7
2
7
EXT
CS
EXT
CS
FB
1
8
1
8
3
22 H
20 H
V
V
L1
IN
IN
L1
= 5V
= 4V
N
Si9410DY
R
100m
N
Si9410DY
R
1N5817
1N5817
SENSE
SENSE
D1
68 F
D1
28k
R1
47 F
C1
C1
140k
R2
C4
200 F
V
C4
100 F
OUT
V
@ 0.5A
OUT
= 12V
= 9V