MAX8717ETI+ Maxim Integrated Products, MAX8717ETI+ Datasheet - Page 12

• Manufacturer Part Number: MAX8717ETI+
• Description: IC CNTRLR PWR SUP 28-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8717ETI+

• Applications: Controller, Notebook Computers
• Voltage - Input: 4 ~ 26 V
• Number Of Outputs: 2
• Voltage - Output: 3.3V, 5V, 1 ~ 5.5 V
• Operating Temperature: 0°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-TQFN Exposed Pad
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Interleaved High-Efficiency, Dual Power-Supply
Controllers for Notebook Computers
The MAX8716/MAX8717/MAX8756/MAX8757 Standard
Application Circuit (Figure 1) generates the 5V/5A and
3.3V/5A typical of the main supplies in notebook com-
puters. The input supply range is 6V to 24V. See Table 1
for component selections, while Table 2 lists the compo-
nent manufacturers.
The MAX8716/MAX8717/MAX8756/MAX8757 contain
two interleaved fixed-frequency, step-down controllers
designed for low-voltage power supplies. The optimal
interleaved architecture guarantees out-of-phase oper-
ation, which reduces the input capacitor ripple.
12
MAX8716
______________________________________________________________________________________
EP
14
15
16
17
18
19
20
21
22
23
24
—
—
—
PIN
MAX8717/
MAX8756/
MAX8757
EP
16
17
18
19
20
21
22
23
24
25
26
27
28
—
Detailed Description
PGOOD1
NAME
AGND
PGND
CSH1
BST1
CSL1
ILIM1
GND
DH1
DL2
V
DL1
LX1
FB1
EP
DD
Low-Side Gate-Driver Output for SMPS2. DL2 swings from PGND to V
Supply Voltage Input for the DL_ Gate Drivers. Connect to a 5V supply.
Power and Analog Ground. Connect backside pad to GND.
Power Ground
Analog Ground. Connect backside pad to AGND.
Low-Side Gate-Driver Output for SMPS1. DL1 swings from PGND to V
Inductor Connection for SMPS1. Connect LX1 to the switched side of the inductor. LX1
is the lower supply rail for the DH1 high-side gate driver.
High-Side Gate-Driver Output for SMPS1. DH1 swings from LX1 to BST1.
Boost Flying Capacitor Connection for SMPS1. Connect to an external capacitor and
diode as shown in Figure 1. An optional resistor in series with BST1 allows the DH1 turn-
on current to be adjusted.
Positive Current-Sense Input for SMPS1. Connect to the positive terminal of the current-
sense element. Figure 8 describes two different current-sensing options.
Negative Current-Sense Input for SMPS1. Connect to the negative terminal of the
current-sense element. Figure 8 describes two different current-sensing options.
Feedback Input for SMPS1. Connect FB1 to V
MAX8716/MAX8717/MAX8757, or a fixed 1.5V for the MAX8756. In adjustable mode,
FB1 regulates to 1V.
SMPS1 Open-Drain Power-Good Output. PGOOD1 is low when SMPS1 is more than
10% below its regulation threshold, during soft-start, and in shutdown.
SMPS1 Peak Current-Limit Threshold Adjustment. Connect ILIM1 to V
default 50mV current-limit threshold. In adjustable mode, the current-limit threshold
across CSH1 and CSL1 is precisely 1/10 the voltage seen at ILIM1 over a 500mV to
2.0V range. The logic threshold for switchover to the 50mV default value is
approximately V
Exposed Pad. Connect exposed backside pad to analog ground.
CC
- 1V.
The MAX8716/MAX8717/MAX8756/MAX8757 switch-
mode power supplies (SMPS) require a 5V bias supply
in addition to the high-power input supply (battery or
AC adapter). V
drive, and V
external 4.5V to 5.5V supply directly to V
nect V
Figure 1. The maximum supply current required is:
where I
and Q
charge specification limits at V
I
BIAS
G_
DD
= I
CC
SMPS 5V Bias Supply (V
Q
CC
are the MOSFET data sheet’s total gate-
to V
G2(NH2)
FUNCTION
is 1.3mA, f
Pin Description (continued)
CC
+ f
DD
CC
is the power rail for the IC. Connect the
SW
CC
is the power rail for the MOSFET gate
) = 1.3mA to 40mA
through an RC filter, as shown in
(Q
for fixed 3.3V output for the
G(NL1)
SW
is the switching frequency,
+ Q
GS
G1(NH1)
= 5V.
CC
DD.
DD.
CC
to enable the
+Q
DD
and V
G2(NL2)
and con-
DD
+
)