RT3614EE
UVLO
Current Balance
Detects the VCC voltage. As VCC overs threshod,
controller issues POR = high and waits VRON. After both
POR and VRON are ready, then controller is enabled.
Per-phase current sense signal is compared with sensed
average current. The comparison result adjusts each phase
PWM width to optimize current and thermal balance.
Loop Control/Protection Logic
Zero Current Detection
It controls power-on/off sequence, protections, power state
transition, and PWM sequence.
Detects whether each phase current crosses zero current.
The result is used for DEM power saving and overshoot
reduction (Anti-overshoot function).
DAC
AQR/ANTIOVS
Generates a reference VID voltage according to the VID
code sent by Control Logic. According to setVID
command, Control Logic dynamically changes VIDvoltage
to the target with required slew rate.
AQR is a new generation of quick response mechanism
(Adaptive Quick Response, AQR) which detects loading
rising edge and allows all PWM to turn on. PWM pulse
width triggered by AQR is adaptive to loading level. AQR
trigger level can be set by PIN-SETTING. ANTIOVS can
help overshoot reduction which detects loading falling edge
and forces all PWM in tri-state until the zero current is
detected.
ERROR AMP
Inverts and amplifies the difference between output voltage
and VIDwith externally set finiteDC gain. The output signal
is COMP for PWM trigger.
PER CSGM
TONGEN/Driver Interface
Senses per-phase inductor current. The outputs are used
for loop response, current balance, zero current detection,
current reporting and over-current protection.
PWM comparator output signal triggers TONGEN to
generate PWM pulse. The PWM sequence is controlled
by loop control. PWM pulse width is determined by
frequency setting, current balance output and adaptive
quick response (AQR) settings. Once AQR is triggered,
VR allows all PWM to turn on at the same time. Driver
Interface provides high/low/tri-state to drive external driver.
In power saving mode, driver interface forces PWM in tri-
state to turn off high side and low side power MOSFET
according to zero current detection output. In addition,
PWM state is controlled by protection logic. Different
protections force required PWM state.
SUM CSGM
Senses total inductor current with RIMON gain adjustment.
SUM CSGM output current ratio can also be set by PIN-
SETTING(Ai[1:0]). It helps wider application range ofDCR
and load line. SUM CSGM output is used for PWM trigger.
RAMP
RAMP helps loop stability and transient response.
PWM CMP
OVP/UVP/OCP
The PWM comparator compares COMP signal and sum
current signal based on RAMP to trigger PWM.
Over-voltage protection/Under-voltage protection/Over-
current protection.
Offset Cancellation
Cancel the current signal/comp voltage ripple issue to
control output voltage accuracy.
Copyright 2019 Richtek Technology Corporation. All rights reserved.
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is a registered trademark of Richtek Technology Corporation.
www.richtek.com
6
DS3614EE-01 December 2019
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
