Buck Regulator. MIC26603-ZA Datasheet

MIC26603-ZA Regulator. Datasheet pdf. Equivalent

MIC26603-ZA Datasheet
Recommendation MIC26603-ZA Datasheet
Part MIC26603-ZA
Description Synchronous DC-to-DC Buck Regulator
Feature MIC26603-ZA; MIC26603-ZA 28V, 6A Hyper Speed Control Synchronous DC-to-DC Buck Regulator SuperSwitcher™ II Gene.
Manufacture Micrel Semiconductor
Datasheet
Download MIC26603-ZA Datasheet





Micrel Semiconductor MIC26603-ZA
MIC26603-ZA
28V, 6A Hyper Speed Control
Synchronous DC-to-DC Buck Regulator
SuperSwitcher™ II
General Description
The Micrel MIC26603-ZA is a constant-frequency,
synchronous buck regulator featuring a unique adaptive
ON-time control architecture. The MIC26603-ZA operates
over an input supply range of 4.5V to 28V and provides a
regulated output of up to 6A of output current. The output
voltage is adjustable down to 0.6V with a guaranteed
accuracy of ±1%, and the device operates at a switching
frequency of 600kHz.
Micrel’s Hyper Speed Controlarchitecture allows for
ultra-fast transient response while reducing the output
capacitance and also makes (High VIN)/(Low VOUT)
operation possible. This adaptive tON ripple control
architecture combines the advantages of fixed-frequency
operation and fast transient response in a single device.
The MIC26603-ZA offers a full suite of features to ensure
protection of the IC during fault conditions. These include
undervoltage lockout to ensure proper operation under
power-sag conditions, internal soft-start to reduce inrush
current, foldback current limit, “hiccup mode” short-circuit
protection, and thermal shutdown. An open-drain Power
Good (PG) pin is provided.
Datasheets and support documentation are available on
Micrel’s web site at: www.micrel.com.
Features
SuperSwitcher™ II
Hyper Speed Control architecture enables
High Delta V operation (VIN = 28V and VOUT = 0.6V)
Small output capacitance
4.5V to 28V voltage input
6A output current capability, up to 95% efficiency
Adjustable output from 0.6V to 5.5V
±1% feedback accuracy
Any Capacitorstable - zero-to-high ESR
600kHz switching frequency
No external compensation
Power Good (PG) output
Foldback current limit and short-circuit protection
Supports safe startup into a pre-biased load
–40°C to +125°C junction temperature range
28-pin 5mm × 6mm QFN package
Applications
Distributed power systems
Communications/networking infrastructure
Set-top box, gateways, and routers
Printers, scanners, graphic cards, and video cards
Typical Application
100
95
90
85
80
75
70
65
60
55
50
0
Efficiency (VIN = 12V)
vs. Output Current
5.0V
3.3V
2.5V
1.8V
1.5V
1.2V
1.0V
0.9V
0.8V
123456
OUTPUT CURRENT (A)
7
8
Hyper Speed Control, SuperSwitcher, and Any Capacitor are trademarks of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
July 16, 2014
Revision 1.1



Micrel Semiconductor MIC26603-ZA
Micrel, Inc.
Ordering Information
Part Number
MIC26603-ZAYJL
Voltage
Adjustable
Switching
Frequency
600kHz
Pin Configuration
MIC26603-ZA
Package
28-Pin 5mm × 6mm QFN
Junction Temperature
Range
–40°C to +125°C
Lead
Finish
Pb-Free
28-Pin 5mm × 6mm QFN (JL)
(Top View)
Pin Description
Pin Number
1
2, 5, 6, 7,
8, 21
3
4, 9, 10,
11, 12
13,14,15,16,
17,18,19
20
Pin Name
PVDD
PGND
NC
SW
PVIN
BST
Pin Function
5V Internal Linear Regulator output: PVDD supply is the power MOSFET gate drive supply voltage
created by internal LDO from VIN. When VIN < +5.5V, PVDD should be tied to the PVIN pins. A 2.2µF
ceramic capacitor from the PVDD pin to PGND (pin 2) must be placed next to the IC.
Power Ground: PGND is the ground path for the buck converter power stage. The PGND pins connect
to the low-side N-Channel internal MOSFET gate drive supply ground, the sources of the MOSFETs,
the negative terminals of input capacitors, and the negative terminals of output capacitors. The loop
for the power ground should be as small as possible and separate from the signal ground (SGND)
loop.
No Connect.
Switch Node output: Internal connection for the high-side MOSFET source and low-side MOSFET
drain. Because of the high-speed switching on this pin, the SW pin should be routed away from
sensitive nodes.
High-Side N-internal MOSFET Drain Connection input: The PVIN operating voltage range is from 4.5V
to 28V. Input capacitors between the PVIN pins and the power ground (PGND) are required and keep
the connection short.
Boost output: Bootstrapped voltage to the high-side N-channel MOSFET driver. A Schottky diode is
connected between the PVDD pin and the BST pin. A boost capacitor of 0.1μF is connected between
the BST pin and the SW pin. Adding a small resistor at the BST pin can reduce the turn-on time of
high-side N-Channel MOSFETs.
July 16, 2014
2
Revision 1.1



Micrel Semiconductor MIC26603-ZA
Micrel, Inc.
MIC26603-ZA
Pin Description (Continued)
Pin Number
22
23
24
25
26
27
28
Pin Name
CS
SGND
FB
PG
EN
VIN
VDD
Pin Function
Current Sense input: The CS pin senses current by monitoring the voltage across the low-side
MOSFET during the OFF-time. The current sensing is necessary for short circuit protection. To sense
the current accurately, connect the low-side MOSFET drain to SW using a Kelvin connection. The CS
pin is also the high-side MOSFET’s output driver return.
Signal Ground: SGND must be connected directly to the ground planes. Do not route the SGND pin to
the PGND pad on the top layer (see “PCB Layout Guidelinesfor details).
Feedback input: Input to the transconductance amplifier of the control loop. The FB pin is regulated to
0.6V. A resistor divider connecting the feedback to the output is used to adjust the desired output
voltage.
Power Good output: Open drain output. The PG pin is externally tied with a resistor to VDD. A high
output is asserted when VOUT > 92% of nominal.
Enable input: A logic level control of the output. The EN pin is CMOS-compatible. Logic high = enable,
logic low = shutdown. In the off state, the supply current of the device is greatly reduced (typically
5µA). Do not leave the EN pin floating.
Power Supply Voltage input: Requires a bypass capacitor to SGND.
5V Internal Linear Regulator output: VDD supply is the power MOSFET gate drive supply voltage and
the supply bus for the IC. VDD is created by internal LDO from VIN. When VIN < +5.5V, VDD should
be tied to PVIN pins. A 1µF ceramic capacitor from the VDD pin to SGND pins must be placed next to
the IC.
July 16, 2014
3
Revision 1.1





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