Chip-dat/TI-dat/TI-Power-dat/TI-power-dat.md
... ...
@@ -58,7 +58,46 @@ TPS7A45xx Low-Noise Fast-Transient-Response 1.5-A Low-Dropout Voltage Regulators
58 58
59 59
[LM78L - LM78L 100-mA Fixed Output Linear Regulator](https://www.ti.com/lit/ds/symlink/lm78l.pdf?ts=1769674083676)
60 60
61
+LM3940 1-A Low-Dropout Regulator for 5-V to 3.3-V Conversion
61 62
63
+The LM3940 is a 1-A low-dropout regulator designed to provide 3.3 V from a 5-V supply.
64
+
65
+
66
+## design
67
+
68
+### parallel
69
+
70
+Two LDOs cannot simply be paralleled to get double the current unless they are specifically designed for current sharing.
71
+
72
+Workaround - Add small ballast resistors (common workaround)
73
+
74
+ LDO1 ──0.1Ω──┐
75
+ ├── Vout
76
+ LDO2 ──0.1Ω──┘
77
+
78
+Resistors force current sharing
79
+
80
+Typical values: 50–200 mΩ
81
+
82
+Trade-offs:
83
+- Voltage drop
84
+- Worse load regulation
85
+- Extra heat
86
+
87
+⚠️ Still not ideal for high precision or high current
88
+
89
+Better solutions (recommended)
90
+
91
+Use one higher-current LDO
92
+- Simplest
93
+- Most reliable
94
+
95
+Use a switching regulator + LDO
96
+- Buck converter for current
97
+- LDO for low noise
98
+
99
+Use a regulator family designed for paralleling
100
+- Some PMICs allow this
62 101
63 102
## ref
64 103
Tech-dat/amplifier-dat/amplifier-dat.md
... ...
@@ -17,7 +17,7 @@
17 17
18 18
M/A-COM’s MAALSS0034 broadband gain stage is a GaAs MMIC amplifier in a lead-free SOT-89 surface mount plastic package. It can be operated from a single 3 to 5 volt supply.
19 19
20
-- [[op-amp-dat]]
20
+- [[op-amp-dat]] - [[LNA-dat]]
21 21
22 22
23 23
## operational amplifiers (op-amps)
Tech-dat/antenna-dat/LNA-dat/LNA-dat.md
... ...
@@ -42,6 +42,17 @@ Weak incoming signals need to be amplified early in the signal chain. A low-nois
42 42
HMC564LC4 - IC GAAS LNA 7-14GHz
43 43
44 44
45
+## noise amplifier
46
+
47
+- [[qorvo-dat]] - [[QPL9504-dat]] - Ultra Low Noise, Flat Gain LNA
48
+
49
+- The QPL9504 is a flat gain, high-linearity, ultra-low noise amplifier in a small 2 x 2 mm surface-mount package. At 5.5 GHz, the amplifier provides 0.76 dB noise figure with 21.6 dB gain and +34 dBm OIP3 while drawing 55 mA bias current. The LNA can be biased from a single positive supply ranging from 3.3 to 5 volts. The device is housed in a green/RoHS-compliant industry-standard 2x2 mm DFN package.
50
+
51
+
52
+
53
+
54
+
55
+
45 56
46 57
## ref
47 58
Tech-dat/tech-dat.md
... ...
@@ -188,7 +188,7 @@
188 188
189 189
- [[USB-dat]] - [[USB-sys-dat]]
190 190
191
-- [[amplifier-dat]] - [[codec-dat]] - [[op-amp-dat]]
191
+- [[amplifier-dat]] - [[codec-dat]] - [[op-amp-dat]] - [[LNA-dat]]
192 192
193 193
194 194