MAX1641EEE+ Maxim Integrated Products, MAX1641EEE+ Datasheet - Page 7

• Manufacturer Part Number: MAX1641EEE+
• Description: IC SW-MODE CUR SOURCE ADJ 16QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1641EEE+

• Function: Charge Management
• Voltage - Supply: 5.5 V ~ 26 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP (0.150", 3.90mm Width)
• Number Of Outputs: 1
• Duty Cycle (max): 100 %
• Output Voltage: 2 V to 24 V
• Mounting Style: SMD/SMT
• Switching Frequency: 500 KHz
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Synchronous Pin: No
• Topology: Buck
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX1640/MAX1641 switch-mode current sources
utilize a hysteretic, current-mode, step-down pulse-
width-modulation (PWM) topology with constant off-
time. Internal comparators control the switching
mechanism. These comparators monitor the current
through a sense resistor (R
TERM. When inductor current reaches the current limit
[(V
and the N-channel FET synchronous rectifier turns on.
Inductor energy is delivered to the load as the current
ramps down. This ramp rate depends on R
inductor values. When off-time expires, the P-channel
FET turns back on and the N-channel FET turns off.
Two digital inputs, D0 and D1, select between four pos-
sible current levels (Table 1). In pulse-trickle mode, the
Figure 1a. Standard Application Circuit
_______________Detailed Description
4.7μF
0.1μF
CS+
47μF
- V
R1
R2
0.1μF
R
TOFF
CS-
Current Source with Synchronous Rectifier
0.01μF
) / R
LDOL
D0
D1
TOFF
REF
SET
CC
IN
_______________________________________________________________________________________
SENSE
MAX1641
GND
], the P-channel FET turns off
PGND
LDOH
PDRV
NDRV
TERM
CS+
CS-
SENSE
0.33μF
1/2 IR7309
) and the voltage at
1/2 IR7309
N
Adjustable-Output, Switch-Mode
100mΩ
BATT
P
47μH
TOFF
R3
R4
and
V
OUT
part operates for 12.5% of the period set by R
resulting in a lower current for pulse-trickle charging.
See the Functional Diagram. Figures 1a and 1b show
the standard application circuits.
The sense resistor, R
levels. Choose between these two levels by holding
D0 high, and toggling D1 either high or low (Table 1).
The fast-charge current level equals V
where V
150mV. Alternatively, calculate this current by V
(13.3R
(13.3R
grams the voltage at SET (Figure 2).
Figure 1b. Standard Application Circuit
0.1μF
4.7μF
47μF
SENSE
SENSE
CS
R1
R2
0.1μF
R
is the full-scale current-sense voltage of
). A resistor-divider from REF to GND pro-
TOFF
). The top-off current equals V
Charge Mode: Programming the
0.01μF
LDOL
D0
D1
TOFF
REF
SET
CC
IN
SENSE
MAX1640
GND
LDOH
, sets two charging current
NDRV
PGND
TERM
PDRV
CS+
CS-
0.33μF
1/2 IR7309
Output Currents
R3
R4
1/2 IR7309
N
CS
/ R
V
P
SENSE
OUT
47μH
100mΩ
BATT
TOFF
SET
REF
7
,
/
/