MAX1678EUA Maxim Integrated Products, MAX1678EUA Datasheet

no-image

MAX1678EUA

Manufacturer Part Number
MAX1678EUA
Description
DC/DC Switching Converters
Manufacturer
Maxim Integrated Products
Datasheet

Specifications of MAX1678EUA

Lead Free Status / Rohs Status
Lead free / RoHS Compliant

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
MAX1678EUA
Manufacturer:
LT
Quantity:
9
Part Number:
MAX1678EUA
Manufacturer:
MAXIM/美信
Quantity:
20 000
Part Number:
MAX1678EUA+T
Manufacturer:
MAXIM/美信
Quantity:
20 000
The MAX1678 is a high-efficiency, low-voltage, syn-
chronous-rectified, step-up DC-DC converter intended
for use in devices powered by 1 to 3-cell alkaline,
NiMH, or NiCd batteries or a 1-cell lithium battery. It
guarantees a 0.87V start-up voltage and features a low
37µA quiescent supply current.
The device includes a 1Ω, N-channel MOSFET power
switch, a synchronous rectifier that acts as the catch
diode, a reference, pulse-frequency-modulation (PFM)
control circuitry, and circuitry to reduce inductor ring-
ing—all in an ultra-small, 1.1mm-high µMAX package.
The output voltage is preset to 3.3V or can be adjusted
from +2V to +5.5V using only two resistors. Efficiencies
up to 90% are achieved for loads up to 50mA. The
device also features an independent undervoltage
comparator (PFI/PFO) and a logic-controlled 2µA shut-
down mode.
19-1381; Rev 0; 7/98
Dual Mode is a trademark of Maxim Integrated Products.
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
INPUT
0.87V TO V
DETECTOR INPUT
Pagers
Remote Controls
Pointing Devices
Personal Medical Monitors
Single-Cell Battery-Powered Devices
LOW-BATTERY
OUT
ON
OFF
High-Efficiency, Step-Up DC-DC Converter
Typical Operating Circuit
________________________________________________________________ Maxim Integrated Products
LX
BATT
SHDN
PFI
General Description
GND
MAX1678
FB
OUT
PFO
Applications
LOW-BATTERY
DETECTOR OUTPUT
OUTPUT
3.3V
1-Cell to 2-Cell, Low-Noise,
Note: To order these devices shipped in tape-and-reel, add a -T
to the part number.
MAX1678EUA
0.87V Guaranteed Start-Up
Up to 90% Efficiency
Built-In Synchronous Rectifier (no external diode)
Ultra-Small µMAX Package, 1.1mm High
37µA Quiescent Current (85µA from 1.5V battery)
2µA Logic-Controlled Shutdown
Power-Fail Detector
Dual Mode™ Output: Fixed 3.3V
45mA Output Current at 3.3V for 1-Cell Input
90mA Output Current at 3.3V for 2-Cell Input
Inductor-Damping Switch Suppresses EMI
PART
TOP VIEW
SHDN
BATT
PFO
PFI
-40°C to +85°C
TEMP. RANGE
3
4
1
2
Ordering Information
Adjustable 2V to 5.5V
MAX1678
Pin Configuration
MAX
8 µMAX
8
7
6
5
PIN-PACKAGE
OUT
LX
GND
FB
Features
1

Related parts for MAX1678EUA

MAX1678EUA Summary of contents

Page 1

... Dual Mode™ Output: Fixed 3.3V 45mA Output Current at 3.3V for 1-Cell Input 90mA Output Current at 3.3V for 2-Cell Input Inductor-Damping Switch Suppresses EMI Applications PART MAX1678EUA Note: To order these devices shipped in tape-and-reel, add the part number. TOP VIEW OUTPUT 3.3V ...

Page 2

Low-Noise, High-Efficiency, Step-Up DC-DC Converter ABSOLUTE MAXIMUM RATINGS BATT, OUT,LX, SHDN to GND ..............................-0.3V to +6.0V OUT, LX Current.......................................................................1A FB, PFI, PFO to GND ................................-0. Reverse Battery Current (T = +25°C) (Note 1) ...............220mA A ...

Page 3

High-Efficiency, Step-Up DC-DC Converter ELECTRICAL CHARACTERISTICS ( 1.3V GND, T SHDN BATT LOAD PARAMETER SYMBOL Maximum Operating Input V Voltage Output Voltage (Fixed Mode) Output Voltage Range (Adjustable Mode) FB Set Voltage ...

Page 4

Low-Noise, High-Efficiency, Step-Up DC-DC Converter (Circuit of Figure 7 (Fixed Mode, 3.3V) or Figure 8 (Adjustable Mode), T EFFICIENCY vs. LOAD CURRENT (V = 2.4V OUT 100 ...

Page 5

High-Efficiency, Step-Up DC-DC Converter (Circuit of Figure 7 (Fixed Mode, 3.3V) or Figure 8 (Adjustable Mode), T EFFICIENCY WITH DIFFERENT INDUCTORS 1.2V BATT 3.3V OUT I = 20mA LOAD ...

Page 6

Low-Noise, High-Efficiency, Step-Up DC-DC Converter (Circuit of Figure 7 (Fixed Mode, 3.3V) or Figure 8 (Adjustable Mode), T SWITCHING WAVEFORM s/div V = 3.3V 1.2V 10mA, C OUT BATT ...

Page 7

High-Efficiency, Step-Up DC-DC Converter BATT 0.5REF PFI PFO RFRDY REF 1.23V REF 0.5REF SHDN Figure 1. Functional Diagram Detailed Description The MAX1678 consists of an internal 1Ω, N-channel MOSFET power switch, a built-in synchronous rectifier that acts as the catch ...

Page 8

Low-Noise, High-Efficiency, Step-Up DC-DC Converter Operating Principle The MAX1678 employs a proprietary constant-peak- current control scheme that combines the ultra-low qui- escent current of traditional pulse-skipping PFM converters with high-load efficiency. When the error comparator detects that ...

Page 9

High-Efficiency, Step-Up DC-DC Converter Pulling the SHDN pin low places the MAX1678 in shut- down mode (I = 2µA typical). In shutdown, the SHDN internal switching MOSFET turns off, PFO goes high impedance, and the synchronous rectifier turns off to ...

Page 10

Low-Noise, High-Efficiency, Step-Up DC-DC Converter Applications Information Output Voltage Selection The MAX1678 operates with a fixed 3.3V or adjustable output. To select fixed-voltage operation, connect FB to GND (Figure 7). For an adjustable output between 2V and ...

Page 11

High-Efficiency, Step-Up DC-DC Converter Capacitor Selection Choose input and output capacitors to service input and output peak currents with acceptable voltage rip- ple. Capacitor ESR is a major contributor to output rip- ple (usually more than 60%). A 10µF, ceramic ...

Page 12

Low-Noise, High-Efficiency, Step-Up DC-DC Converter ___________________Chip Information TRANSISTOR COUNT: 840 12 ______________________________________________________________________________________ Package Information ...

Related keywords