Datasheet
Gate Driver
Anti
Shoot-Through
Power Save Mode
Feedback Divider
+
-
Frequency
Control
R
1
R
2
L
GND
Soft-Start
EN VIN
Current Limit
Detect
Undervoltage
Lockout
Bias Supply
Bandgap
Thermal
Shutdown
Negative Inductor
Current Detect
VIN
MODE
V = 0.8 V
REF
V
REF
C
I
1µH
C
4.7µF
O
Switching
VOUT
DC/DC CONVERTER
2.2µF
TPS82670
,
TPS82671
,
TPS82672
,
TPS82673
,
TPS82674
,
TPS82675
TPS82676
,
TPS82677
,
TPS826711
,
TPS826721
,
TPS826745
,
TPS826765
www.ti.com
SLVSAI0H –OCTOBER 2010–REVISED OCTOBER 2014
9 Detailed Description
9.1 Overview
The TPS8267x is a stand-alone, synchronous, step-down converter. The converter operates at a regulated 5.5-
MHz frequency pulse width modulation (PWM) at moderate to heavy load currents. At light load currents, the
TPS8267x converter operates in power-save mode with pulse frequency modulation (PFM).
The converter uses a unique frequency-locked ring-oscillating modulator to achieve best-in-class load and line
response. One key advantage of the non-linear architecture is that there is no traditional feed-back loop. The
loop response to change in V
O
is essentially instantaneous, which explains the transient response. Although this
type of operation normally results in a switching frequency that varies with input voltage and load current, an
internal frequency lock loop (FLL) holds the switching frequency constant over a large range of operating
conditions.
Combined with best-in-class load and line-transient response characteristics, the low quiescent current of the
device (approximately 17μA) helps to maintain high efficiency at light load while that current preserves a fast
transient response for applications that require tight output regulation.
The TPS8267x integrates an input current limit to protect the device against heavy load or short circuits and
features an undervoltage lockout circuit to prevent the device from misoperation at low input voltages. Fully
functional operation is permitted down to 2.1V input voltage.
9.2 Functional Block Diagram
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Product Folder Links: TPS82670 TPS82671 TPS82672 TPS82673 TPS82674 TPS82675 TPS82676 TPS82677
TPS826711 TPS826721 TPS826745 TPS826765