UCC2941-3 Datasheet, PDF (1/11 Pages) List of Unclassifed Manufacturers – 1V Synchronous Boost Converter

1V Synchronous Boost Converter
application
INFO
available
UCC2941-3/-5/-ADJ
UCC3941-3/-5/-ADJ
FEATURES
• 1V Input Voltage Operation Startup
Guaranteed Under Full Load on Main
Output With Operation Down to 0.4V
• Input Voltage Range of 1V to V_OUT +
0.5V
• 500mW Output Power at Battery
Voltages as Low as 0.8V
• Secondary 9V Supply From a Single
Inductor
• Adjustable Output Power Limit Control
• Output Fully Disconnected in
Shutdown
• Adaptive Current Mode Control for
Optimum Efficiency
• 8µA Shutdown Supply Current
DESCRIPTION
The UCC3941 family of low input voltage single inductor boost converters
are optimized to operate from a single or dual alkaline cell, and step up to
a 3.3V, 5V, or an adjustable output at 500mW. The UCC3941 family also
provides an auxiliary 9V 100mW output, primarily for the gate drive supply,
which can be used for applications requiring an auxiliary output such as a
5V supply by linear regulating. The primary output will start up under full
load at input voltages typically as low as 0.8V, with a guaranteed maximum
of 1V, and will operate down to 0.4V once the converter is operating, maxi-
mizing battery utilization.
Demanding applications such as Pagers and PDA’s require high efficiency
from several milli-watts to several hundred milli-watts, and the UCC3941
family accommodates these applications with >80% typical efficiencies
over the wide range of operation. The high efficiency at low output current
is achieved by optimizing switching and conduction losses along with low
quiescent current. At higher output current the 0.25Ω switch, and 0.4Ω syn-
chronous rectifier, along with continuous mode conduction, provide high ef-
ficiency. The wide input voltage range on the UCC3941 family can
accommodate other power sources such as NiCd and NiMH.
Other features include maximum power control and shutdown control.
Packages available are the 8-pin SOIC (D) and 8-pin DIP (N or J).
SIMPLIFIED BLOCK DIAGRAM AND APPLICATION CIRCUIT
10µF
22µH
+ _{0.8V TO VOUT +0.5V}
8V
VGD
2
10µF
VIN
3
STARTUP
CIRCUITRY
SW
8
0.4Ω
0.25Ω
OPEN=SD
MODULATOR CONTROL CIRCUIT
SYNCHRONOUS RECTIFICATION CIRCUITRY
ANTI-CROSS CONDUCTION
STARTUP
MULTIPLEXING LOGIC
MAXIMUM INPUT POWER CONTROL
ADAPTIVE CURRENT CONTROL
SD
4
UCC3941-ADJ
–
+
1.25V
*FOR UCC3941-ADJ ONLY:
PIN 7 = SGND & PGND, PIN 6 = OUTPUT SENSE FEEDBACK, FB.
SLUS242 - JULY 1999
UCC3941-3 = 3.3V
UCC3941-5 = 5.0V
UCC3941-ADJ = 1.30V TO 6V
VOUT
1
100µF
PLIM
5
*SGND/FB
6
PGND
7
UDG-98147