PRELIMINARY INFORMATION
®
SP6122
Low Voltage, Micro 8, PFET, Buck Controller
Ideal for 1A to 5A, Small Footprint, DC-DC Power Converters
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Optimized for Single Supply, 3V - 7V Applications
High Efficiency, Greater than 90% Possible
Small Micro 8 Package
20ns/1nF PFET Output Driver
Fast Transient Response
Open Drain Fault Output Pin
Internal, 2ms, Soft Start Circuit (300kHz)
Accurate 1.5% Reference
Factory Programmable Output Voltage
Factory Programmable Frequency, up to 600kHz
Loss-less Adjustable Current Limit with High side
R
DS(ON)
Sensing
Hiccup or Lock-up Fault Modes
Minimum On-Time, “Jitter & Frequency Stabilized”
PFM Control: Simplifies Input and Output Filter
design, provides great Light Load Efficiency and
allows for Low Drop Out Regulation.
Low 5µA Sleep Mode Quiescent Current
Low 300µA Protected Mode Quiescent Current
Ultra Low, 150µA Unprotected Mode Quiescent
Current
Output Over Voltage Protection
V
CC
1
FFLAG 2
V
OUT
3
ENABLE 4
8 PDRV
SP6122
8 Pin
µSOIC
7 GND
6 I
SET
5 I
SENSE
APPLICATIONS
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Video Cards
High Power Portable
Microcontrollers
I/O & Logic
Industrial Control
Distributed Power
Low Voltage Power
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DESCRIPTION
The
SP6122
is a PWM/PFM minimum on-time controller designed to work from a single
5V or 3.3V input supply. It is engineered specifically for size and minimum components
count, simplifying the transition from a linear regulator to a switcher solution. However,
unlike other “micro” parts, the
SP6122
has an array of value added features like optional
hiccup mode, over current protection, TTL enable, “jitter and frequency stabilization” and
a fault flag pull down pin. Combined with reference and driver specifications usually found
on more expensive integrated circuits, the
SP6122
delivers great performance and value
in a micro 8 package.
V
IN
3.0V to 7.0V
RSET
CV
CC
V
CC
PDRV
®
Available in 300kHz or 600kHz
1.5V Adjustable
1.8V, 2.5V and 3.3V Fixed
MP2
FFLAG
FFLAG
V
OUT
GND
SP6122
I
SET
I
SENSE
ENABLE
ENABLE
L1
DFLY
1A to 5A
V
OUT
C
OUT
Rev. 5/22/01
SP6122 Low Voltage, Micro 8, PFET, Buck Controller
© Copyright 2001 Sipex Corporation
1
PRELIMINARY INFORMATION
ABSOLUTE MAXIMUM RATINGS
These are stress ratings only and functional operation of
the device at these ratings or any other above those
indicated in the operation sections of the specifications
below is not implied. Exposure to absolute maximum
rating conditions for extended periods of time may affect
reliability.
V
CC ..............................................................................................................
7V
All other pins ...................................... -0.3V to V
CC
+0.3V
Peak Output Current < 10µs
PDRV ......................................................................... 2A
Storage Temperature .............................. -65°C to 150°C
Power Dissipation
Lead Temperature (Soldering, 10 sec) ................. 300°C
ESD Rating ...................................................... 2kV HBM
SPECIFICATIONS
Unless otherwise specified: 0°C < T
AMB
< 70°C, 3.0V < V
CC
< 5.5V, C
PDRV
= 1nF, V
ENABLE
= V
CC
, V
FFLAG
= V
CC
,
I
SET
= I
SENSE
= V
CC
, GND = 0V
PARAMETER
QUIESCENT CURRENT
V
CC
Supply Current,
OVC Enabled
V
CC
Supply Current,
OVC Disabled
V
CC
Supply Current,
OVC Disabled, Ultra Low IQ
V
CC
Supply Current, Sleep Mode
REFERENCE
Output Voltage, Initial Accuracy
Output Voltage, Over Line,
Load and Temperature
PWM/PFM Reference
Comparator Hysteresis
V
OUT
Input Current
OSCILLATOR
Oscillator Frequency
MIN
TYP
MAX
UNITS
CONDITIONS
-
-
-
-
300
250
150
5
400
-
-
15
µA
µA
µA
µA
No Switching, I
SET
= I
SENSE
= V
CC
No Switching, I
SET
= I
SENSE
= 0
No Switching, ISET = 0,
I
SENSE
=V
CC
Enable=0
VR*0.985
VR*0.980
-
-
VR
VR
5
23
VR*1.015
VR*1.020
-
-
V
V
mV
µA
VR = Factory Set Voltage,
see Note
VR = Factory Set Voltage,
see Note
Internal Hysteresis at Feedback
Terminal
V
OUT
= VR
F*0.7
F
F*1.3
kHz
F = Factory Set Frequency,
see Note
Measured during Startup
Minimum Pulse Width during
Startup (Blanking Time)
Soft Start
Soft Start Ramp Time
(600kHz part)
Soft Start Ramp Time
(300kHz part)
Soft Start Voltage when
PDRV Switches
-
200
-
ns
-
1
-
ms
V
OUT
= VR – 30mV, Measure
time from ENABLE = 1V to
PDRV Low
V
OUT
= VR – 30mV, Measure
time from ENABLE = 1V to
PDRV Low
Measure VSoft Start when
PDRV goes Low. (internal)
-
2
-
ms
-
250
-
mV
Rev. 5/22/01
SP6122 Low Voltage, Micro 8, PFET, Buck Controller
© Copyright 2001 Sipex Corporation
2
PRELIMINARY INFORMATION
SPECIFICATIONS
Unless otherwise specified: 0°C < T
AMB
< 70°C, 3.0V < V
CC
< 5.5V, C
PDRV
= 1nF, V
ENABLE
= V
CC
, V
FFLAG
= V
CC
,
I
SET
= I
SENSE
= V
CC
, GND = 0V
PARAMETER
MIN
TYP
MAX
UNITS
CONDITIONS
RDS OVER CURRENT COMPARATOR
Over Current Comparator
Threshold Voltage
Threshold Voltage Temperature
Coefficient
I
SET
Sink Current
I
SET
Current Temperature
Coefficient
I
SENSE
Input Bias Current
I
SET
, I
SENSE
Common Mode
Input Range
Over Current Peak Detection
Time Constant
ENABLE INPUT & FFLAG OUTPUT
ENABLE Threshold
ENABLE Pin Source Current
FFLAG Sink Current
GATE DRIVER
PDRV Rise Time
PDRV Fall Time
20
20
75
75
ns
ns
0.5V to 4.5V
4.5V to 0.5V
-
2
3
1.1
5
7.5
-
10
V
µA
mA
V(FFLAG) = 1V
130
-
18
-
-
2.0
-
150
3300
23
4000
-
-
10
180
-
28
-
100
V
CC
-
mV
ppm/°C
µA
ppm/°C
nA
V
µs
Current into I
SET
25°C only
V(I
SET
) - V(I
SENSE
) 25°C only
NOTE: Available Output Voltages: 1.5V Adj., 1.8V, 2.5V, 3.3V
Available Frequencies: 300kHz, 600kHz
Rev. 5/22/01
SP6122 Low Voltage, Micro 8, PFET, Buck Controller
© Copyright 2001 Sipex Corporation
3
PRELIMINARY INFORMATION
PIN DESCRIPTION
PIN #
1
2
3
4
PIN NAME
V
CC
FFLAG
V
OUT
ENABLE
DESCRIPTION
Main Supply Pin: Decouple close to pin.
Fault Flag Pull-down Pin: Sinks current during a fault condition. Can
be hooked up to ENABLE to initiate Hiccup Timing.
Regulated Output Voltage: This voltage is divided internally and
compared to a 1.5%, 1.25V reference at the PWM/PFM comparator.
Enable Input: Floating this pin or pulling above 1.1V enables the part.
Pulling this pin to less than 0.65V will disable the part. If FFLAG is
hooked to ENABLE, a capacitor on ENABLE will control hiccup timing.
Negative Input to the Over Current Amplifier/Comparator: This input
is subtracted from the I
SET
input and gained by a factor of 3.3. The
output of this amplifier is compared with a 0.5V threshold, yielding a
150mV threshold. This threshold has a 3300 ppm/°C temperature
coefficient. If the subtraction exceeds 150mV, charge is pumped into
a capacitor until the capacitor hits V
CC
/2. At this time, the over current
fault is activated. If I
SET
= 0V and I
SENSE
= V
CC
, the part enters an
unprotected, 150µA quiescent current mode.
Positive Input to the Over Current Amplifier: 23µA flows into the I
SET
pin if it is pulled through a resistor to V
IN
. This current has a
4000ppm/°C temperature coefficient and can be used via external
resistor to raise the overcurrent trip point from 150mV to some higher
value. If I
SET
= 0V and I
SENSE
= 0V, the part enters an unprotected,
250µA quiescent current mode.
Power and Analog Ground: Hook directly to output ground.
Drive for PFET High Side Switch: 1nF/20ns Output Driver.
5
I
SENSE
6
I
SET
7
8
GND
PDRV
Rev. 5/22/01
SP6122 Low Voltage, Micro 8, PFET, Buck Controller
© Copyright 2001 Sipex Corporation
4
PRELIMINARY INFORMATION
BLOCK DIAGRAM
0.5V/ms (300kHz)
1.0V/ms (600kHz)
Soft Start
SS
-
+
Reset
Dominant
R
SS
Latch
S
QB
PFET OFF
ENABLE 4
1.25V
Reference
-
+
1V
Reset
Dominant
POR R
QB
Run
Latch
S
Q
Soft Start Clock
V
OUT
* K1
T
ON
Min On Time Clock
RESET
Dominant
S
QB
Loop
Latch
R
Q
PFET OFF
7 GND
Blank
Start On Time
1 V
CC
Reference
Comparator
Driver
Logic
PFET
Driver
8 PDRV
-
V
OUT
3
X K1
+
I
SET
6
23µA
(4000 ppm/°C)
PDRV
Over Current
(Gated S&H)
200ns Blanking
One Shot
+
X 3.3
I
SENSE
5
+
-
POR
Reset
Dominant
S
Q FAULT
R
POR
2 FFLAG
-
500mV
(3300 ppm/°C)
I
SET
I
SENSE
I
SET
< 1V
Low IQ
Rev. 5/22/01
SP6122 Low Voltage, Micro 8, PFET, Buck Controller
© Copyright 2001 Sipex Corporation
5
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