MAX17007GTI+ Maxim Integrated Products, MAX17007GTI+ Datasheet - Page 24

• Manufacturer Part Number: MAX17007GTI+
• Description: IC CTRLR QPWM GRAPHICS 28TQFN
• Manufacturer: Maxim Integrated Products
• Series: Quick-PWM™r

Specifications of MAX17007GTI+

• Applications: Power Supplies
• Current - Supply: 1.7mA
• Voltage - Supply: 4.5 V ~ 26 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 28-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX17007/MAX17008 feature preset and
adjustable output voltages for both SMPSs, and
dynamic output voltages for SMPS1. In combined
mode, the output voltage is set by REFIN1, and all fea-
tures for SMPS1 output-voltage configuration and
dynamic voltage changes apply to the combined out-
put. Figure 9 is the SMPS target decode block diagram.
Connect REFIN1 to V
preset 1.05V. Connect FB2 to REF to set the SMPS2
Dual and Combinable QPWM Graphics
Core Controllers for Notebook Computers
Figure 9. SMPS Target Decode Block Diagram
24
REF (2.0V)
REF - 0.3V
REF (2.0V)
FB2
TARGET1
V
V
CC
REFIN1
CC
______________________________________________________________________________________
- 1V
- 1V
10.5R
9.5R
5R
8R
7R
1.05V
1.5V
0.7V
Preset/Adjustable Output Voltages
(A) SMPS1 TARGET DECODE
(B) SMPS2 TARGET DECODE
(FB1 = V
(FB2 = REF)
CC
PRESET
PRESET
to set the SMPS1 voltage to
CC
)
(Dual-Mode Feedback)
Output Voltage
(FB2 = V
COMBINE
CC
TARGET1
)
TARGET2
voltage to preset 1.5V. The SMPS1 output voltage can
be adjusted up to 2V by changing REFIN1 voltage with-
out using an external resistive voltage-divider. The out-
put voltage of SMPS2 can be adjusted with an external
resistive voltage-divider between CSL2 and GND with
the center tap connected to FB2 (Figure 10). Choose
R
mately 10kΩ and solve for R
to FB2) using the equation:
The MAX17007/MAX17008 regulate the valley of the
output ripple, so the actual DC output voltage is higher
than the slope compensated target by 50% of the out-
put ripple voltage. Under steady-state conditions, the
MAX17007/MAX17008s’ internal integrator corrects for
this 50% output ripple voltage error, resulting in an out-
put-voltage accuracy that is dependent only on the off-
set voltage of the integrator amplifier provided in the
Electrical Characteristics table.
The MAX17007/MAX17008 regulate the output to the
voltage set at REFIN1. By changing the voltage at
REFIN1 (Figure 1), the MAX17007/MAX17008 can be
used in applications that require dynamic output volt-
age changes between two set points. For a step-volt-
age change at REFIN, the rate of change of the output
voltage is limited either by the internal 9.5mV/µs slew-
rate circuit or by the component selection—inductor
current ramp, the total output capacitance, the current
limit, and the load during the transition—whichever is
slower. The total output capacitance determines how
much current is needed to change the output voltage,
while the inductor limits the current ramp rate.
Figure 10. Setting V OUT2 with a Resistive Voltage-Divider
FB2LO
MAX17007
MAX17008
(resistance from FB2 to GND) to be approxi-
CSH2
CSL2
GND
DL2
LX2
FB2
R
FB HI
2
Dynamic Output Voltages (REFIN1)
=
R
FB2LO
R
FB LO
N
L2
2
FBHI
L2
⎛
⎜
⎝
R
V
FB2HI
0 7
CSL
(resistance from CSL2
.
V
R
2
SENSE2
−
1
⎞
⎟
⎠
C
OUT2