15

LT1713/LT1714

GN Package

16-Lead Plastic SSOP (Narrow 0.150)

(LTC DWG # 05-08-1641)

Dimensions in inches (millimeters) unless otherwise noted.

PACKAGE DESCRIPTIO

GN16 (SSOP) 1098

* DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH

SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD

FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE

12

3

4

5

6

7

8

0.229 – 0.244

(5.817 – 6.198)

0.150 – 0.157**

(3.810 – 3.988)

16 15 14 13

0.189 – 0.196*

(4.801 – 4.978)

12 11 10 9

0.016 – 0.050

(0.406 – 1.270)

0.015

± 0.004

(0.38

± 0.10)

× 45°

0

° – 8° TYP

0.007 – 0.0098

(0.178 – 0.249)

0.053 – 0.068

(1.351 – 1.727)

0.008 – 0.012

(0.203 – 0.305)

0.004 – 0.0098

(0.102 – 0.249)

0.0250

(0.635)

BSC

0.009

(0.229)

REF

TYPICAL APPLICATIO

Rail-to-Rail Pulse Width Modulator

Using the LT1714

Binary modulation schemes are used in order to improve

efficiency and reduce physical circuit size. They do this by

reducing the power dissipation in the output driver tran-

sistors. In a normal Class A or Class AB amplifier, voltage

drop and current flow exist simultaneously in the output

transistors and power losses proportional to V • I occur.

In a binary modulation scheme, the output transistors,

whether bipolar or FET, are switched hard-on and hard-off

so that voltage drops do not occur simultaneously with

current flow. The circuit of Figure 9 shows an example of

a binary modulation scheme, in this case pulse width

modulation.

The LT1809 is configured as an integrator in order to

generate nice linear rail-to-rail voltage ramps. The polarity

of the ramp is determined by the output of the LT1714’s

comparator A into R4. The heavy hysteresis of R1 around

the LT1714’s comparator A combined with the feedback of

the LT1809 force the devices to perpetually reverse each

other, resulting in a 1MHz triangle wave. This constitutes

the usual first half of any pulse width modulator, but the

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-

tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.