MAX8568AETE+ Maxim Integrated Products, MAX8568AETE+ Datasheet - Page 8

• Manufacturer Part Number: MAX8568AETE+
• Description: IC BATT MANAGE LITH 16-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8568AETE+

• Function: Back-Up Management
• Battery Type: Lithium-Ion (Li-Ion); Nickel-Metal Hydride (NiMH)
• Voltage - Supply: 2.8 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Complete Backup-Management ICs
for Lithium and NiMH Batteries
8
_______________________________________________________________________________________
PIN
EP
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
TERMV
STRTV
NAME
PGND
BKSU
INOK
CHGI
GND
LDO
OD1
OD2
NI/LI
BKV
REF
BK
LX
IN
—
Main Battery Input. Connect to a 2.8V to 5.5V battery or other power source. Bypass with a 4.7µF
ceramic capacitor to GND.
Backup Battery Input. Connect to an NiMH or rechargeable lithium backup battery. Connect a ceramic
bypass capacitor from BK to GND. See the Step-Up Capacitor Selection section for more details.
Power Ground. Connect PGND to the ground side of the BK input capacitor and BKSU output
capacitor. Use this connection as the star point for all grounds. See the PC Board Layout and Routing
section for specific instructions regarding PGND.
Inductor Connection for Low-I
Step-Up Converter Output. Bypass with a 10µF to 22µF ceramic capacitor to PGND. The BKSU output
voltage is set to either 3.3V or 2.5V without resistors, or to an adjustable voltage with an external
resistor-divider. See the Setting the Step-Up Converter Voltage section.
2.5V (MAX8568A) or 1.8V (MAX8568B), 10mA LDO Output for Memory Supply. LDO is powered from
BKSU. Bypass with a 4.7µF ceramic capacitor to GND.
11Ω Open-Drain Output. OD1 drives the gate of an external pMOS switch.
11Ω Open-Drain Output. OD2 drives the gate of an external pMOS switch.
Selects NiMH or Rechargeable Lithium Backup Battery. Connect NI/LI to BKSU if an NiMH backup
battery is used. Connect NI/LI to GND if a rechargeable lithium backup battery is used.
Sets the BKSU Output Voltage. Connect to GND for 3.3V output at BKSU. Connect to BKSU for 2.5V
output. Connect to the midpoint of a resistor-divider connected from BKSU to GND for adjustable
output. See the Setting the Step-Up Converter Voltage section.
Main Battery Monitor. When V
step-up converter and LDO turn on, and OD1 and OD2 go high impedance.
Sets Backup Battery Charge Current. Connect a resistor from CHGI to GND to set the charge current.
See the Setting the Charge Current section for details.
Ground. Connect to the exposed paddle. Star all grounds at the BKSU output capacitor ground.
Sets Fast-Charge Start Voltage for NiMH. See the Using an NiMH Backup Battery section.
Sets Fast-Charge Stop Voltage for NiMH, as Well as the Battery Regulation Voltage for Both
Rechargeable Lithium and Maximum Voltage for NiMH. See the Using a Lithium Backup Battery
section and the Using an NiMH Backup Battery section.
Reference Output. Bypass with a 0.22µF ceramic capacitor to GND.
Exposed Paddle. Connect to the analog ground plane. EP also functions as a heatsink. Solder to the
circuit-board analog ground plane.
INOK
Q
Step-Up DC-DC Converter
falls below 2.43V, charging stops and backup mode starts. The
FUNCTION
Pin Description