NEC UPC1933GR Datasheet
DATA SHEET
BiCMOS INTEGRATED CIRCUIT
µ
µ
PC1933
µ µ
DC-DC CONVERTER CONTROL IC
DESCRIPTION
PC1933 is an IC that controls a low-voltage input DC-DC conver ter. This IC is suitable for an operation with3-V,
The
µ
3.3-V input or a lithium ion secondary battery input, because the minimum operating supply voltage is 2.5 V.
Because of its wide operating voltage range, it can also be used to control DC-DC converters that use an AC adapter for
input.
FEATURES
Low supply voltage: 2.5 V (MIN.)
•
Operating voltage range: 2.5 to 20 V (breakdown voltage: 30 V)
•
Timer latch circuit for short-circuit protection.
•
Ceramic capacitor with low capacitance (0.1
•
Open drain output (1 cannel: This output can be used to control a step-down converter, a step-up converter.)
•
Dead time is internally fixed to 85 %.
•
Soft start function (with a circuit to convert the timer latch circuit.)
•
ORDERING INFORMATION
Part Number Package
PC1933GR 8-pin plastic SOP (5.72 mm (225))
µ
F) can be used fo r short-circuit protection.
µ
The information in this document is subject to change without notice. Before using this document, please
confirm that this is the latest version.
Not all devices/types available in every country. Please check with local NEC representative for
availability and additional information.
Document No. G13690EJ3V0DS00 (3rd edition)
Date Published April 2000 NS CP (K)
Printed in Japan
The mark ★ shows major revised points.
1998
BLOCK DIAGRAM
µ
µ
PC1933
µ µ
FB
87 65
MOS input
Internal
fixed
voltage
12
I
I
E/A PWM
–
+
Timer latch for
short-circuit
protection section
DLY V
R
Oscillation
section
Soft start
select switch
DTC
(Internal fixed)
T
–
+
+
Reference
voltage
section
34
CC
OUTGND
MOS output
V
REF
2
Data Sheet G13690EJ3V0DS00
PIN CONFIGURATION (Top View)
8-pin plastic SOP (5.72 mm (225))
••••
µµµµ
PC1933GR
µ
µ
PC1933
µ µ
DLY
V
V
REF
I
I
CC
1
2
3
4
8
7
6
5
FB
R
T
GND
OUT
PIN FUNCTIONS
Pin No. Symbol Function Pin No. Symbol Function
1IIError amplifier inverted input 5 OUT Open-drain output
2 DLY Short-circuit protection 6 GND Ground
3VCCPower supply 7 R
4V
REF
Reference voltage output 8 FB Error amplifier output
T
Frequency setting resistor connection
Data Sheet G13690EJ3V0DS00
3
µ
µ
PC1933
µ µ
CONTENTS
1. ELECTRICAL SPECIFICATIONS................................................................................................................5
2. CONFIGURATION AND OPERATION OF EACH BLOCK....................................................................11
2.1 Reference V oltage Generator ...........................................................................................................................11
2.2 Oscillator ...........................................................................................................................................................11
2.3 Under Voltage Lock-out Circuit........................................................................................................................11
2.4 Error Amplifier...................................................................................................................................................11
2.5 PWM Comparator..............................................................................................................................................12
2.6 Timer Latch-Method Short Circuit Protection Circuit....................................................................................12
2.7 Output Circuit....................................................................................................................................................12
3. NOTES ON USE........................................................................................................................................13
3.1 Setting the Output Voltage ...............................................................................................................................13
3.2 Setting the Oscillation Frequency...................................................................................................................13
3.3 Preventing Malfunction of the Timer Latch-Method Short Circuit Protection Circuit..................................13
3.4 ON/OFF Control.................................................................................................................................................14
3.5 Maximum Duty Limit.........................................................................................................................................15
3.6 Notes on Actual Pattern Wiring........................................................................................................................15
4. APPLICATION EXAMPLE ......................................................................................................................... 16
4.1 Application Example.........................................................................................................................................16
4.2 List of External Parts........................................................................................................................................16
5. PACKAGE DRAWING................................................................................................................................17
6. RECOMMENDED SOLDERING CONDITIONS .......................................................................................18
4
Data Sheet G13690EJ3V0DS00
µ
µ
PC1933
µ µ
1. ELECTRICAL SPECIFICATIONS
====
Absolute Maximum Ratings (unless otherwise specified, TA
Parameter Symbol Ratings Unit
Supply voltage V
Output voltage V
Output current (open drain output) I
Total power dissipation P
Operating ambient temperature T
Storage temperature T
CC
O
O
T
A
stg
Caution Product quality may suffer if the absolute maximum rating is exceeded even momentarily for any
parameter. That is, the absolute maximum ratings are rated values at which the product is on the verge
of suffering physical damage, and therefore the product must be used under conditions that ensure
that the absolute maximum ratings are not exceeded.
25
°°°°
C)
30 V
30 V
21 mA
480 mW
−
20 to + 85
−
55 to + 150
°
C
°
C
Recommended Operating Conditions
Parameter Symbol Ratings Unit
Supply voltage V
Output voltage V
Output current I
Operating temperature T
Oscillation frequency f
CC
O
O
A
OSC
2.5 20 V
020V
20 mA
−
20
20 800 kHz
+
85
°
C
Caution The recommended operating range may be exceeded without causing any problems provided that the
absolute maximum ratings are not exceeded. However, if the device is operated in a way that exceeds
the recommended operating conditions, the margin between the actual conditions of use and the
absolute maximum ratings is small, and therefore thorough evaluation is necessary. The recommended
operating conditions do not imply that the device can be used with all values at their maximum values.
Data Sheet G13690EJ3V0DS00
5
µ
µ
PC1933
µ µ
Electrical Characteristics (unless otherwise specified, TA = 25
°°°°
C, VCC
====
3 V, f
OSC
= 100 kHz)
Block Parameter Symbol Conditions MIN. TYP. MAX. Unit
Under
voltage
Lock-out
section
Reference
Voltage
section
section
PWM
Start-up voltage V
Operation stop voltage V
Hysteresis voltage V
Reset voltage (timer latch) V
Reference voltage V
CC (L-H)
CC (H-L)
H
CCR
REF
Line regulation REG
Load regulation REG
Temperature coefficient
OSC
f
setting accuracy
OSC
f
total stabilit y
Maximum duty D
∆
V
OSC
∆
f
OSC
∆
f
MAX.
IN
L
REF
REF
I
= 0.1 mA 1.57 V
REF
I
= 0.1 mA 1.5 V
REF
I
= 0.1 mA 30 70 mV
REF
I
= 0.1 mA 1.0 V
REF
I
= 1 mA 2.0 2.1 2.2 V
2.5 V≤V
0.1 mA≤I
/∆T−20 °C≤T
RT = 18 k
−
20 °C≤T
2.5 V≤V
CC
≤
20 V 2 12.5 mV
REF
≤
1 mA 2 7.5 mV
A
≤+
Ω−
A
≤+
CC
≤
20 V
85 °C, I
85 °C,
REF
= 0 A 0.5 %
20
−
20
+
+
85 %
comparator
section
Error
Amplifier
section
Soft start time t
Input threshold voltage V
Input bias current I
Open loop gain A
Unity gain f
Maximum output voltage (+)
Maximum output voltage (−)
Output sink current I
Output source current I
Output
section
Drain cutoff current I
Output ON voltage V
Rise time t
Fall time t
Short-circuit
Protection
section
Input sense voltage V
UV sense voltage V
Source current on short-circuiting I
Delay time t
Overall Circuit operation current I
SS
ITH
B
v
unity
OM
V
OM
V
Osink
Osource
LEAK
OL
r
f
TH
UV
OUV
DLY
CC
+
−
DLY
C
= 0.1 µF50ms
0.285 0.3 0.315 V
−
100
+
VO = 0.3 V 70 80 dB
VO = 0.3 V 1.5 MHz
IO = −45 µA1.62V
IO = 45 µA 0.02 0.5 V
VFB = 0.5 V 0.8 1.4 mA
VFB = 1.6 V
−
70
−
VO = 30 V 100
RL = 150
RL = 150
RL = 150
Ω
Ω
Ω
0.2 0.6 V
50 ns
60 ns
1.75 1.92 2.05 V
0.8 0.85 V
1.0 1.6 2.7
DLY
C
= 0.1 µF50ms
VCC = 3 V 1.4 2.6 3.9 mA
30 %Oscillation
50 %
100 nA
µ
45
µ
µ
A
A
A
Caution Connect a capacitor of 0.01 to 10
µ
PC1933
6
µ
µ
F to the V
µ µ
REF
pin.
4
6
Data Sheet G13690EJ3V0DS00
C
REF
= 0.01 to 10 F
µ
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