TS1935
1.6MHz Boost Converter
with 30V Internal FET Switch
SOT-25
Pin Definition:
1. SW
2. Ground
3. FB
4. EN
5. Input
General Description
The TS1935 switching regulator is current –mode boost
converters operating at fixed frequency of 1.6MHz.
The use of SOT-25 made possible by the minimal power
loss of the internal 1.6A switch, and use of small inductor
and capacitors result in the industry’s highest power
density. The 30V internal switch makes these solutions
perfect for boosting to voltages up to 30V.
These parts have a logic-level shutdown pin that can be
used to reduce quiescent current and extend battery life.
Protection is provided through cycle-by-cycle current
limiting and thermal shutdown. Internal compensation
simplifies and reduces component count.
Typical Application Circuit
Features
●
●
●
●
●
●
●
30V DMOS FET Switch
2.7V to 5.5V Input Range
1.6MHz Switching Frequency
Low R
DSON
DMOS FET
Switch Current up to 1.6A
Low Shutdown Current <1uA
Use Tiny Capacitors and Inductor
Cycle-by-Cycle Current Limiting
●
●
●
●
●
●
Application
White LED Current Source
Digital Still Cameras
Portable Electronics
PDA’s and Palm-Top Computers
Local Boost Regulator
Ordering Information
Part No.
TS1935CX5 RF
Package
SOT-25
Packing
3Kpcs / 7” Reel
1/8
Version: A07
TS1935
1.6MHz Boost Converter
with 30V Internal FET Switch
Absolute Maximum Rating
Parameter
Input Voltage
EN, V
FB
Voltage
SW Voltage
Ambient Temperature Range
Junction Temperature Range
Storage Temperature Range
Symbol
V
IN
V
EN
, V
FB
V
SW
T
A
T
J
T
STG
Limit
6
V
IN
30
-40 to +85
-40 to +125
-65 to +150
Unit
V
V
V
o
o
o
C
C
C
ESD Classification
B*
Note: Stress above the listed absolute maximum rating may cause permanent damage to the device
* HBM B: 2000~3999V
Thermal Information
Parameter
Thermal Resistance* (Junction to Case)
Thermal Resistance* (Junction to Ambient)
Internal Power Dissipation
Maximum Junction Temperature
Solder Iron (10 Sec)**
* Measure
Ө
JC
on center of molding compound if IC has no tab.
** MIL-STD-202G210F
Symbol
Ө
JC
Ө
JA
P
D
Maximum
81
260
400
150
350
Unit
o
o
C/W
C/W
o
o
mW
C
C
Pin Description
Pin Number
1
2
Pin Name
Power Switch Input.
SW
GND
Description
This is the drain of the internal NMOS power switch.
Minimize the metal trace area connected to this pin to minimize EMI.
Ground. Tie directly to ground plan.
Output voltage feedback input.
Set the output voltage by selecting values for R1 and R2 using:
3
FB
Connect the ground of the feedback network to a GND plane.
Enable, active high.
4
EN
The enable pin is an active high control. Tie this pin above 2V to enable the device.
Tie this pin below 0.4V to turn off the device.
Analog and Power input. Input Supply Pin.
Place bypass capacitor as close to Vin as possible.
5
IN
2/8
Version: A07
TS1935
1.6MHz Boost Converter
with 30V Internal FET Switch
Electrical Specifications
(Ta = 25
o
C, V
IN
=5V, EN=V
IN
, I
L
=0A unless otherwise noted)
Parameter
Input Voltage
Feedback Pin Bias Current
Regulated Feedback Voltage
FB Voltage Line Regulation
Symbol
V
IN
I
FB
V
FB
Test Condition
V
FB
=1.23V
V
IN
=3V
V
IN
=2.7V
R
L
= 43Ω
V
IN
=3.3V
V
IN
=5V
V
IN
=2.7V
R
L
= 43Ω
Ta = 25 C
Ta = -40~ +85 C
V
IN
=5V,
Ta = -40~ +85 C
o
o
o
Min
2.5
--
1.205
--
5.4
8
13
3.75
5
8.75
1.5
1.2
--
--
--
Typ
--
60
1.23
0.02
7
10
17
5
6.5
11
1.8
--
0.4
--
0.5
--
0.1
2
--
400
--
0
0
1.6
0.1
93
--
--
Max
5.5
500
1.255
--
--
--
--
--
--
--
--
--
0.6
0.7
0.7
0.8
1
--
3
--
500
--
2
1.85
2
--
1.4
Unit
V
nA
V
%/V
∆V
FB
/∆V
IN
2.7V
≤
V
IN
≤
5.5V
Minimum Output Voltage Under Load V
OUT (MIN)
V
V
IN
=3.3V
V
IN
=5V
Switch Current Limit
I
CL
A
Switch ON Resistance
R
DSON
V
IN
=3.3V,
Ta = -40~ +85 C
o
A
--
--
Ta = 25 C
V
IN
=5V,
Ta = -40~ +85 C
Ta = 25 C
V
IN
=5V,
Ta = -40~ +85 C
o
o
o
o
Shutdown Current
I
SD
V
EN
=0V
FB = 1.15V
(Switching)
uA
mA
--
--
--
--
--
--
Quiescent Current
I
Q
FB = 1.3V
(No Switching)
uA
EN Pin Bias Current
Switching Frequency
Switching Leakage Current
Maximum Duty Cycle
EN Input Threshold (High)
(Shutdown)
EN Input Threshold (Low)
(Enable the device)
I
EN
f
SW
I
SW
D
MAX
V
EH
V
EL
EN = 0
EN = 5V
Ta = -40~ +85 C
V
EN
=0V
Ta = -40~ +85 C
Ta = -40~ +85 C
Ta = -40~ +85 C
o
o
o
o
uA
MHz
uA
%
1
--
86
--
2
V
--
3/8
Version: A07
TS1935
1.6MHz Boost Converter
with 30V Internal FET Switch
Function Block Diagram
Pin Description
The TS1935 is a switching converter IC that operates at a fixed frequency (1.6MHz) for fast transient response over a
wide input voltage range and incorporates pulse-by-pulse current limiting protection. Because this is current mode
control, a 33mΩ sense resistor in series with the switch FET is used to provide a voltage (which is proportional to the
FET current) to both the input of the pulse width modulation (PWM) comparator and the current limit amplifier.
At the beginning of each cycle, the S-R lath turns on the FET. As the current through the FET increases, a voltage
(proportional to this current) is summed with the ramp coming from the ramp generator and then fed into the input of
the PWM comparator. When this voltage exceeds the voltage on the other input (coming from the Gm amplifier), the
latch resets and turns the FET off. Since the signal coming from the Gm amplifier is derived from the feedback (which
samples the voltage at the output), the action of the PWM comparator constantly sets the correct peak current through
the FET to keep the output voltage in regulation.
Q1 & Q2 align with R3 – R6 form a bandgap voltage reference used by the IC to hold the output in regulation. The
currents flowing through Q1 & Q2 will be equal, and the feedback loop will adjust the regulated output to maintain this .
Because of this, the regulated output is always maintained at a voltage level equal to the voltage at the FB node
“multiplied up” by the ratio of the output resistive divider.
The current limit comparator feeds directly into the flip-flop that derives the switch FET. If the FET current reaches the
limit threshold, the FET is turned off and the cycle terminates the pulse regardless of the status of the output of the
PWM comparator.
4/8
Version: A07
TS1935
1.6MHz Boost Converter
with 30V Internal FET Switch
Electrical Characteristics Curve
Figure 1. I
Q
Vin (Active) vs. Temperature
Figure 2. I
Q
Vin (Idle) vs. Temperature
Figure 3. Oscillator Frequency vs. Temperature
Figure 4. Max. Duty Cycle vs. Temperature
Figure 5. Feedback Bias Current vs. Temperature
Figure 6. Efficiency vs. Load Current
5/8
Version: A07
京公网安备 11010802033920号
EEWORLD
