MAX17512ATP+ Maxim Integrated, MAX17512ATP+ Datasheet - Page 8

• Manufacturer Part Number: MAX17512ATP+
• Description: Current & Power Monitors & Regulators High Speed Valley Current Regulator
• Manufacturer: Maxim Integrated

Specifications of MAX17512ATP+

• Product: Current Regulators
• Supply Voltage - Max: 18 V
• Supply Voltage - Min: 6.5 V
• Input Voltage Range: 6.5 V to 18 V

The MAX17512 IC is optimized for implementing high
efficiency, 6.5V to 18V wide input voltage range, and
synchronous, step-down valley current regulators. The
device employs a valley constant on-time, current-mode-
control architecture with integrated power MOSFETs to
deliver load currents up to 6A. The device incorporates a
very high-performance PWM comparator that has very low
hysteresis and propagation delay. It regulates the inductor
current to the valley current-command voltage applied at
the ICMD pin. The device also offers selectable on-time
that decides the amount of ripple in the inductor current.
The architecture of the device allows for simple implemen-
tation of multiple parallel modules by driving the respec-
tive ICMD pin with the same current-command voltage.
Internal low R
efficiency at heavy loads, while minimizing critical induct-
ance, making the layout design a much simpler task than
that of discrete solutions. The device improves efficiency
by means of an innovative break-before-make scheme
that minimizes body diode conduction time, while ensur-
ing that there is no shoot through in the MOSFETs. The
device’s simple layout and footprint assure first-pass
success in new designs.
The device includes an open-drain FLT output that goes
high when the device is ready to commence operation.
See the
17, 18, 19
13–16
PIN
12
20
—
Block Diagram
High-Speed, Constant On-Time, Valley Current
PGND1–PGND4 Power Ground. Connect with a short wide trace to the input decoupling-capacitor ground terminal.
LX1, LX2, LX3
DSON
NAME
SGND
BST
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integrated switches ensure high
Detailed Description
for more information.
Signal Ground. Connect SGND to the SGND plane. Connect SGND and PGND at a single point.
External Inductor Connection. Connect LX_ to the switched side of the inductor.
Boost Flying Capacitor. Connect a ceramic capacitor with a minimum value of 47nF between BST
and LX_.
Exposed Pad for Thermal Dissipation. Ensure that the exposed pad connects to a large copper
plane that is electrically connected to the SGND pin of the IC.
Regulator for Tracking Applications
The device is designed to operate over a 6.5V to 18V
input supply range. The PVIN_ pins are connected to
the drain of the internal high-side MOSFET. The AVIN pin
connects to the input of an internal linear regulator. The
output of the linear regulator is available at the V
An internal linear regulator (V
supply to power the internal control functions and driver
circuitry. The internal linear regulator is powered from the
AVIN pin. When using the internal V
the AVCC and PVCC pins are connected together. To
minimize IC power dissipation, the AVCC and PVCC pins
can be connected to the external 5V power supply.
The maximum regulator input voltage (AVIN) is 18V (min).
Bypass V
Bypass the output of the linear regulator (V
2.2FF ceramic capacitor to SGND. When V
than 6.5V, V
can source up to 50mA to supply the device, power the
low-side gate driver, and recharge the external boost
capacitor when V
A flying bootstrap capacitor is connected between LX_
and BST to provide the gate-driver voltage to the internal
high-side n-channel MOSFET. Upon startup, an internal
low-side switch connects LX_ to ground and charges
the BST capacitor to PVCC. Once the BST capacitor is
charged, the internal low-side switch is turned off and the
BST capacitor voltage provides the necessary enhance-
ment voltage to turn on the high-side switch. A 47nF, 16V
ceramic capacitor located as close as possible to the
device is used.
FUNCTION
IN
High-Side Gate-Driver Supply (BST)
CC
Pin Description (continued)
to PGND with a 10FF ceramic capacitor.
is typically 5V. The V
CC
is connected to AVCC and PVCC.
Linear Regulator (V
CC
Input Voltage Range
MAX17512
) provides a 5V nominal
CC
CC
linear regulator,
linear regulator
IN
CC
is higher
CC
) with a
pin.
CC
)