R34DS0034EU0101 Rev.1.01

Page 21

Mar 13, 2024

ISL73006SLH Datasheet

reach the NOCL, the ISL73006SLH initiates soft-start when VOUT is pulled below the regulation set point. The

device is disabled and enters the low current shutdown state when EN is < 0.3V. When a transition to a shutdown

state occurs, the LX output is forced to a hi-Z state.

5.10 Thermal Protection

The device has integrated thermal protection. When the internal temperature reaches ~ +158°C, the regulator

stops switching. After the internal temperature falls below ~ +130°C, the device resumes operation through

soft-start. For continuous operation, do not exceed the +150°C junction temperature rating.

5.11 PWM Control and Compensation

The ISL73006SLH employs constant frequency peak current-mode pulse-width modulation (PWM) control for

faster transient response and pulse-by-pulse current limiting. The current loop consists of the current-sensing

circuit, slope compensation ramp, and PWM comparator.

Any regulator design starting point is knowing the operating conditions and design goals. These would include the

input and output voltages, the switching frequency, the maximum transient current step, and the maximum

transient output voltage tolerance. The following compensation equations guide completing an external slope and

loop control compensation design.

5.12 Slope Compensation

The ISL73006SLH offers user-adjustable slope compensation using a resistor (RSLOPE) from the SLOPE pin to

ground to optimize the device performance and stability across the entire PWM duty-cycle range. Slope

compensation is a technique in which the current feedback signal is modified by adding slope, that is, a linearly

increasing voltage over time. You can set the external slope compensation ramp with a resistor from the slope pin

to ground.

For applications with a maximum duty cycle of less than 50%, slope compensation can improve noise immunity,

particularly at lighter loads. For applications with a greater than 50% duty cycle, you need slope compensation to

prevent instability, seen as a sub-harmonic oscillation of the switching LX node. The minimum slope

compensation required is -VOUT/2 × output inductor (LOUT).

5.13 External Configuration Application Implementation Equations

This section guides the design for the slope and loop compensations along with the loop bandwidth and limiting

the output current transient voltage response. Use Equation 2 to set the inductor downslope.

The compensation slope is:

Due to inductor tolerances and increased noise immunity, Renesas recommends using SL= SCOMP (deadbeat

control) so:

Due to headroom issues, RSLOPE value must be within 25kΩ ≤ RSLOPE ≤ 100kΩ.

Internal slope compensation is set to maximum slope compensation of 0.324.

(EQ. 2)

(EQ. 3)

(EQ. 4)

SL

VOUT

L

----------------

=

SCOMP

A

s

------

162

RSLOPE k



500

-------------------------------------





=

RSLOPE k



62

VOUT V



L

H



-------------------------

=