Maxim MAX766EPA, MAX766ESA, MAX766MJA, MAX765MJA, MAX766C-D Datasheet

19-0176; Rev 0; 6/94

Evaluation Kit

Available

High-Efficiency, Low IQDC-DC Inverters

-5V/-12V/-15V or Adjustable,

_______________General Description

The MAX764/MAX765/MAX766 inverting switching regu­lators are highly efficient over a wide range of load cur­rents, delivering up to 1.5W. A unique, current-limited,
pulse-frequency-modulated (PFM) control scheme com­bines the benefits of traditional PFM converters with the
benefits of pulse-width-modulated (PWM) converters.
Like PWM converters, the MAX764/MAX765/MAX766 are
highly efficient at heavy loads. Yet because they are PFM
devices, they use less than 120µA of supply current (vs.
2mA to 10mA for a PWM device).

The input voltage range is 3V to 16V. The output volt­age is preset at -5V (MAX764), -12V (MAX765), or -15V
(MAX766); it can also be adjusted from -1V to -16V
using two external resistors (Dual ModeTM). The maxi­mum operating VIN- V

differential is 20V.

OUT

These devices use miniature external components; their
high switching frequencies (up to 300kHz) allow for less
than 5mm diameter surface-mount magnetics. A stan­dard 47µH inductor is ideal for most applications, so no
magnetics design is necessary.

An internal power MOSFET makes the MAX764/MAX765/
MAX766 ideal for minimum component count, low- and
medium-power applications. For increased output drive
capability or higher output voltages, use the
MAX774/MAX775/MAX776 or MAX1774, which drive an
external power P-channel MOSFET for loads up to 5W.

________________________Applications

LCD-Bias Generators
Portable Instruments
LAN Adapters
Remote Data-Acquisition Systems
Battery-Powered Applications

__________Typical Operating Circuit

____________________________Features

♦ High Efficiency for a Wide Range of Load Currents
♦ 250mA Output Current
♦ 120µA Max Supply Current
♦ 5µA Max Shutdown Current
♦ 3V to 16V Input Voltage Range
♦ -5V (MAX764), -12V (MAX765), -15V (MAX766),

or Adjustable Output from -1V to -16V

♦ Current-Limited PFM Control Scheme
♦ 300kHz Switching Frequency
♦ Internal, P-Channel Power MOSFET

______________Ordering Information

PART

MAX764CPA

MAX764CSA
MAX764C/D 0°C to +70°C
MAX764EPA
MAX764ESA -40°C to +85°C
MAX764MJA -55°C to +125°C 8 CERDIP**
MAX765CPA
MAX765CSA
MAX765C/D 0°C to +70°C
MAX765EPA
MAX765ESA -40°C to +85°C
MAX765MJA -55°C to +125°C 8 CERDIP**

Ordering Information continued on last page.

* Dice are tested at T
**Contact factory for availability and processing to MIL-STD-883.

TEMP. RANGE PIN-PACKAGE

0°C to +70°C
0°C to +70°C

-40°C to +85°C 8 Plastic DIP

0°C to +70°C 8 Plastic DIP
0°C to +70°C

-40°C to +85°C 8 Plastic DIP

= +25°C, DC parameters only.

A

8 Plastic DIP
8 SO
Dice*

8 SO

8 SO
Dice*

8 SO

__________________Pin Configuration

MAX764/MAX765/MAX766

INPUT

3V TO 15V

ON/OFF

V+

LX

MAX764

SHDN

REF

FB

________________________________________________________________

OUT

GND

47µH

OUTPUT

-5V

TOP VIEW

OUT

SHDN

REF

1

FB

2

MAX764
MAX765

3

MAX766

4

DIP/SO

Maxim Integrated Products

Call toll free 1-800-998-8800 for free samples or literature.

LX

8

V+

7

V+

6

GND

5

1

-5V/-12V/-15V or Adjustable,
High-Efficiency, Low IQDC-DC Inverters

ABSOLUTE MAXIMUM RATINGS

V+ to GND..............................................................-0.3V to +17V

OUT to GND...........................................................+0.5V to -17V

Maximum Differential (V+ to OUT) ......................................+21V

REF, SHDN, FB to GND ...............................-0.3V to (V+ + 0.3V)

LX to V+..................................................................+0.3V to -21V

LX Peak Current ...................................................................1.5A

Continuous Power Dissipation (T

Plastic DIP (derate 9.09mW/°C above +70°C) ............727mW

SO (derate 5.88mW/°C above +70°C) .........................471mW

CERDIP (derate 8.00mW/°C above +70°C) .................640mW

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

= +70°C)

A

ELECTRICAL CHARACTERISTICS

(V+ = 5V, I

V+ Input Voltage Range
Supply Current
Shutdown Current

MAX764/MAX765/MAX766

FB Input Current

Output Current and Voltage
(Note 1)

Reference Voltage

REF Load Regulation

Efficiency (Note 2)

SHDN Input Voltage High
SHDN Input Voltage Low

LOAD

= 0mA, C

= 0.1µF, TA= T

REF

to T

MIN

MAX76_C/E

V+ V

MAX76_M
V+ = 16V, SHDN < 0.4V

S

I

SHDN

I

V

V+ = 16V, SHDN > 1.6V
V+ = 10V, SHDN > 1.6V
3V ≤ V+ ≤ 16V
MAX76_C
MAX76_E

I

FB

MAX76_M
MAX764, -4.8V ≤ V
MAX765C/E, -11.52V ≤ V

OUT

MAX765M, -11.52V ≤ V
MAX766, -14.40V ≤ V
MAX76_C
MAX76_E

REF

MAX76_M
0µA ≤ I
3V ≤ V+ ≤ 16V

0mA ≤ I
4V ≤ V+ ≤ 6V

10mA ≤ I
VIN= 5V

V+ = 16V, SHDN = 0V or V+
3V ≤ V+ ≤ 16V

IH

3V ≤ V+ ≤ 16V V0.4V

IL

, unless otherwise noted. Typical values are at TA= +25°C.)

MAX

≤ 100µA

REF

LOAD

LOAD

Operating Temperature Ranges

MAX76_C_A ........................................................0°C to +70°C

MAX76_E_A .....................................................-40°C to +85°C

MAX76_MJA ..................................................-55°C to +125°C

Maximum Junction Temperatures

MAX76_C_A/E_A ..........................................................+150°C

MAX76_MJA .................................................................+175°C

Storage Temperature Range ............................-65°C to +160°C

Lead Temperature (soldering, 10sec) ............................+300°C

CONDITIONS

3.0 16.0

3.5
90 120I

2
15

OUT

≤ 100mA

≤ 100mA,

≤ 5.2V

OUT

OUT

≤ -15.60V

OUT

MAX76_C/E
MAX76_M

V

≤ 12.48V

≤ 12.48V

= -5V

OUT

= -15V

OUT

150 260

68 120
50 120
35 105

1.4700 1.5 1.5300

1.4625 1.5 1.5375 V

1.4550 1.5 1.5450
410
415

80
82V

±50
±70
±90

UNITSMIN TYP MAXSYMBOLPARAMETER

µA

mV-10 10FB Trip Point

nA

mA

mV

µV/V40 100REF Line Regulation

%/mA0.008Load Regulation (Note 2)

%/V0.12Line Regulation (Note 2)

%

µA±1SHDN Leakage Current

V1.6V

2 _______________________________________________________________________________________

-5V/-12V/-15V or Adjustable,

High-Efficiency, Low IQDC-DC Inverters

ELECTRICAL CHARACTERISTICS (continued)

(V+ = 5V, I

LX Leakage Current

Peak Current at LX
Maximum Switch On-Time
Minimum Switch Off-Time

Note 1: See Maximum Output Current vs. Supply Voltage graph in the
Note 2: Circuit of Figure 2.

LOAD

= 0mA, C

= 0.1µF, TA= T

REF

MIN

to T

, unless otherwise noted. Typical values are at TA= +25°C.)

MAX

CONDITIONS

MAX76_C

+ (V+) ≤ 20V

ILXI

MAX76_E
MAX76_M

V

+ (V+) ≥ 10V

OUT

I

I

V

PEAK

ON

OFF

OUT

I

+ (V+) ≥ 10V

I

Typical Operating Characteristics

correlation to switch on-time, switch off-time, on-resistance, and peak current rating.

UNITSMIN TYP MAXSYMBOLPARAMETER

±5
±10 µA
±30

Ω1.4 2.5LX On-Resistance

A0.5 0.75I
µs12 16 20t
µs1.8 2.3 2.8t

. Guarantees are based on

__________________________________________Typical Operating Characteristics

(V+ = 5V, V

100

90
80
70
60
50
40

EFFICIENCY (%)

30
20
10

0

= -5V, TA= +25°C, unless otherwise noted.)

OUT

EFFICIENCY vs. LOAD CURRENT

V+ = 5V

0.1 10 1000

MAX764

V+ = 10V

V+ = 15V

CIRCUIT OF FIGURE 2

= -5V ±4%

V

OUT

1 100

LOAD CURRENT (mA)

MAX764-01

EFFICIENCY vs. LOAD CURRENT

100

V+ = 8V

90
80
70
60
50
40

EFFICIENCY (%)

30
20
10

0

0.1 10 1000

MAX765

V+ = 5V

CIRCUIT OF FIGURE 2

= -12V ±4%

V

OUT

1 100

LOAD CURRENT (mA)

MAX764-02

EFFICIENCY vs. LOAD CURRENT

100

90
80
70
60
50
40

EFFICIENCY (%)

30
20
10

0

0.1 10 1000

MAX766

V+ = 5V

CIRCUIT OF FIGURE 2

= -15V ±4%

V

OUT

1 100

LOAD CURRENT (mA)

MAX764/MAX765/MAX766

MAX764-03

_______________________________________________________________________________________ 3

-5V/-12V/-15V or Adjustable,
High-Efficiency, Low IQDC-DC Inverters

____________________________Typical Operating Characteristics (continued)

(V+ = 5V, V

= -5V, TA= +25°C, unless otherwise noted.)

OUT

MAXIMUM OUTPUT CURRENT

600

500

400

300

200

100

MAXIMUM OUTPUT CURRENT (mA)

0

4.0

3.5

MAX764/MAX765/MAX766

3.0

2.5

2.0

1.5

1.0

SHUTDOWN CURRENT (µA)

0.5
0

7.2

7.1

7.0

6.9

6.8

6.7

6.6

6.5

6.4

SWITCH ON/OFF-TIME RATIO (µs/µs)

6.3

6.2

vs. SUPPLY VOLTAGE

CIRCUIT OF FIGURE 2

V

= -5V

OUT

V

= -12V

OUT

V

= -15V

OUT

3

4 5 6 7 8 9 10 11 12 13 14 15 16

SUPPLY VOLTAGE (V)

SHUTDOWN CURRENT

vs. TEMPERATURE

V+ = 15V

V+ = 8V

V+ = 4V

-60

-40 -20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)

SWITCH ON/OFF-TIME RATIO

vs. TEMPERATURE

V+ = 5V

-60

-40 -20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)

MAX764 -04

NO-LOAD SUPPLY CURRENT (µA)

MAX764 -07

MAXIMUM SWITCH ON-TIME (µs)

MAX764 -10

START-UP SUPPLY VOLTAGE (V)

NO-LOAD SUPPLY CURRENT

100

95
90
85
80
75
70
65
60

17.0

16.8

16.6

16.4

16.2

16.0

15.8

15.6

15.4

15.2

15.0

vs. SUPPLY VOLTAGE

3

4 5 6 7 8 9 10 11 12 13 14 15 16

SUPPLY VOLTAGE (V)

MAXIMUM SWITCH ON-TIME

vs. TEMPERATURE

V+ = 5V

-60

-40 -20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)

START-UP SUPPLY VOLTAGE

8
7
6
5
4
3
2
1
0

vs. OUTPUT CURRENT

CIRCUIT OF FIGURE 2

0

50 100 150 200 250 300

OUTPUT CURRENT (mA)

V+ = 15V

110
105

MAX764 -05

100

95
90
85
80
75
70
65
60

NO-LOAD SUPPLY CURRENT (µA)

55
50

-60

-40 -20 0 20 40 60 80 100 120 140

2.60

2.55

MAX764 -08

2.50

2.45

2.40

2.35

2.30

MINIMUM SWITCH OFF-TIME (µs)

2.25

2.20

-60

10,000

MAX764 -11

1000

100

10

LX LEAKAGE CURRENT (nA)

1

20

NO-LOAD SUPPLY CURRENT

vs. TEMPERATURE

V+ = 15V

V+ = 5V

TEMPERATURE (°C)

MINIMUM SWITCH OFF-TIME

vs. TEMPERATURE

V+ = 15V

V+ = 5V

-40 -20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)

LX LEAKAGE CURRENT

vs. TEMPERATURE

IV

I + (V+) = 20V

OUT

30 40 50 60 70 80 90 100 110 120 130

TEMPERATURE (°C)

MAX764 -06

MAX764 -09

MAX764-12

4 _______________________________________________________________________________________