_______________Detailed Description

Output Characteristics

The MAX1647/MAX1648 contain both a voltage-

regulation loop and a current-regulation loop. Both

loops operate independently of each other. The volt-

age-regulation loop monitors BATT to ensure that its

voltage never exceeds the voltage set point (V0). The

current-regulation loop monitors current delivered to

BATT to ensure that it never exceeds the current-limit

set point (I0). The current-regulation loop is in control

as long as BATT voltage is below V0. When BATT volt-

age reaches V0, the current loop no longer regulates,

and the voltage-regulation loop takes over. Figure 5

shows the V-I characteristic at the BATT pin.

Chemistry-Independent

Battery Chargers

______________________________________________________________________________________

11

Table 1b. Component Suppliers

D2

C5

R5

M1

M2

R1

BATTERY

L1

C7

D1

D3

D4

DC SOURCE

R3

THM

REF

CCI

C6

C1

T

C2

R2

C3

C4

R8

R9

R10

R11

R4

MAX1648

DCIN

VL

CCV

SETV

SETI

BST

LX

DLO

PGND

DHI

CS

BATT

AGND

7.5V–28V

Figure 4. MAX1648 Typical Operating Circuit

(847) 639-1469

(847) 639-6400

Coilcraft

(516) 435-1824

(516) 435-1110

(803) 626-3123

(803) 946-0690

AVX

Central Semiconductor

(561) 241-9339

(561) 241-7876

Coiltronics

FAX

PHONE

MANUFACTURER

(512) 992-3377

(512) 992-7900

IRC

(310) 322-3332

(310) 322-3331

(605) 665-1627

(605) 668-4131

Dale

IR

(805) 867-2698

(805) 867-2555

NIEC

(603) 224-1430

(603) 224-1961

(408) 970-3950

(408) 988-8000

Siliconix

Sprague

(847) 956-0702

(847) 956-0666

Sumida

(516) 864-7630

(516) 543-7100

Zetex