1.2MHz Low-Cost,

High-Performance Chargers

______________________________________________________________________________________

11

CSA

A = 17.5V/V

CSSN

CSSP

Gm =

2.8

μA/mV

IINP

GMS

CSIN

CSIP

GMI

ISET

26mV

CHARGER

SHUTDOWN

CELL

SELECT

LOGIC

BATT

VCTL

GMV

CC

LOWEST

VOLTAGE

CLAMP

CSI

60mV

PWM

FILTER

DHI

DLO

PGND

LX

BST

LEVEL

SHIFT

HIGH-SIDE

DRIVER

LOW-SIDE

DRIVER

CCMP

IMIN

IMAX

IZX

10mV

OVP

DC-DC

CONVERTER

110mV

10mV

BDIV

BDIV

VCTL + 100mV

5.4V LINEAR

REGULATOR

4.2V

REFERENCE

DCIN

LDO

POWER

FAIL

LDO

GND

BATT

ACOK

LDO

ACIN

MAX17005

MAX17006

MAX17015

CSA

A = 17.5V/V

Figure 2. Functional Diagram

The MAX17005/MAX17006/MAX17015 feature a volt-

age-regulation loop (CCV) and two current-regulation

loops (CCI and CCS). The loops operate independently

of each other. The CCV voltage-regulation loop moni-

tors BATT to ensure that its voltage never exceeds the

voltage set by VCTL. The CCI battery charge current-

regulation loop monitors current delivered to BATT to

ensure that it never exceeds the current limit set by

ISET. The charge current-regulation loop is in control as

long as the battery voltage is below the set point. When

the battery voltage reaches its set point, the voltage-

regulation loop takes control and maintains the battery

voltage at the set point. A third loop (CCS) takes control

and reduces the charge current when the adapter cur-

rent exceeds the input current limit.

The MAX17005/MAX17006/MAX17015 have single-

point compensation. The two current loops are internal-

ly compensated while the voltage loop is compensated

with a series RC network at CC pin. See the

CC Loop

Compensation section for the resistor and capacitor

selection. A functional diagram is shown in Figure 2.