MAX1865TEEP+T Maxim Integrated Products, MAX1865TEEP+T Datasheet - Page 11

• Manufacturer Part Number: MAX1865TEEP+T
• Description: IC PWR SUPPLY CONTROLLER 20QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1865TEEP+T

• Applications: Power Supply Controller
• Voltage - Input: 4.5 ~ 28 V
• Current - Supply: 1.4mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-QSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

the voltage across the load. Under overload conditions,
when the inductor current exceeds the selected cur-
rent-limit (see the
high-side MOSFET is not turned on at the rising edge of
the clock and the low-side MOSFET remains on to let
the inductor current ramp down.
The MAX1864/MAX1865 operate in a forced-PWM
mode, so even under light loads the controller main-
tains a constant switching frequency to minimize cross-
regulation errors in applications that use a transformer.
The low-side gate-drive waveform is the complement of
the high-side gate-drive waveform, which causes the
inductor current to reverse under light loads.
Figure 1. Standard MAX1864 Application Circuit
xDSL/Cable Modem Triple/Quintuple Output
Setting the Current Limit section), the
______________________________________________________________________________________
1μF
1μF
C2
C1
C
8.2nF
100kΩ
COMP
R
R
47kΩ
COMP
POK
FB
IN
VL
ILIM
POK
COMP
MAX1864
D1
CENTRAL CMPSH-3
GND
OUT
FB2
BST
FB3
DH
DL
B2
B3
LX
10Ω
R
C
0.1μF
DL
R
10Ω
BST
DH
30kΩ
10kΩ
R3
10kΩ
10kΩ
R4
R1
R2
4700pF
220Ω
C
2200pF
R
R
220Ω
C
BE3
BE3
BE2
BE2
N
N
H
L
Q2
Q1
1
T1
C
470μF
The MAX1864/MAX1865s’ current-sense circuit ampli-
fies (A
the high-side MOSFET’s on-resistance (R
I
the internal slope compensation signal are summed
together (V
inverting input. The PWM comparator turns-off the high-
side MOSFET when V
back voltage (V
further than 5mm from the controller, and connect IN
and LX to the MOSFET using Kelvin sense connections
to guarantee current-sense accuracy and improve
stability.
INPUT
9V TO 18V
IN
INDUCTOR
C7
10μF
C4
10μF
C6
10μF
C3
10μF
V
V
OUT3
OUT2
100mA
V
300mA
V
= 5.0V
= 5) the current-sense voltage generated by
= 2.5V
D2
NIHON EP05Q03L
OUT
C
470μF
C5
470μF
OUT
1A
). This amplified current-sense signal and
= 3.3V
SUM
T1
COMP)
) and fed into the PWM comparator’s
NL, NH: INTERNATIONAL RECTIFIER
Power Supplies
Q1: TIP30
Q2: 2N3905
IRF7303
SUM
. Place the high-side MOSFET no
exceeds the integrated feed-
Current-Sense Amplifier
DS(ON)
11
✕