TDA8385 Datasheet, PDF (13/21 Pages) NXP Semiconductors – Control circuit for a Self-Oscillating Power Supply SOPS

Philips Semiconductors
Control circuit for a Self-Oscillating
Power Supply (SOPS)
Preliminary specification
TDA8385
CHARACTERISTICS
V_P = 15 V; I₃ = 200 µA; T_amb = 25 °C; unless otherwise specified.
SYMBOL
PARAMETER
CONDITIONS
MIN.
Supply
V_P
V₁₆
V_16(hys)
I₁₆
V₁₁
supply voltage (pin 16)
supply initialization level
internal fixed hysteresis
supply current
supply voltage ripple rejection
7.9
7.1
2.5
active LED output −
see Figs 13 and 14 −
Reference voltage
V₃
reference voltage at pin 3
0.52
Error amplifier
V₉
I₉
I₁₁
I₁₁
G_o
B
∆V₉/∆T
V₅
threshold voltage error amplitude
2.4
input current feedback input
−
sink current output
V₁₁ = 80 mV
400
source current output
open loop gain
V₁₁ = 2.5 V
500
−
unity gain bandwidth
−
temperature coefficient
−
threshold for switching output
V_diff = 1.25 V;
−
V₄ = 2 V; V₁₃ = 0 V;
V₇ > V₉; I₂ = 2 mA
Transfer characteristic generator
I₄/I₃
current ratio
V₄ = 0.5 V
0.23
V₅
threshold for switching output
V₄ = 0.5 V; V₁₃ = 0 V;
V₇ > V₉; I₂ = 2 mA
T_on(min)
V₉ = 0 V
0.4 − V_os
V_fb = 20%
V₉ = 0.4 V
−
V_fb = 50%
V₉ = 1 V
1.4 − V_os
V_fb = 80%
V₉ = 1.6 V
−
clamp
V₉ = 2.25 V
2.4 − V_os
t_PLH
response time pulse width
note 2
−
modulation pin 5 to pin 2
LOW-to-HIGH
t_PHL
response time pulse width
note 2
−
modulation pin 5 to pin 2
HIGH-to-LOW
Feed forward
V₅
threshold for switching output
(V_fo)
I₁₃
input bias current
V₄ = 0.5 V; V₁₃ = 0 V;
V₇ = V₉ = 3 V;
I₂ = 2 mA; V₁₁ = 1 V
V₁₃ = 0 V
0.6 − V_os
−
TYP.
MAX.
−
20
7.5
7.9
−
2.55
−
20
60
−
0.55
0.58
2.5
2.6
−
0.5
−
−
−
−
100
−
600
−
±300 × 10^−6 −
V_diff − V_os(1) −
0.25
0.27
0.5 − V_os
0.9 − V_os
1.5 − V_os
2.1 − V_os
−
−
0.6 − V_os
−
1.6 − V_os
−
2.6 − V_os
700
−
1
0.7 − V_os 0.8 − V_os
−
1
UNIT
V
V
V
mA
mV
V
V
µA
µA
µA
dB
kHz
K^−1
V
V
V
V
V
V
ns
µs
V
µA
March 1994
14